7825643280 has 800 divisors, whose sum is σ = 34966761984. Its totient is φ = 1576599552.

The previous prime is 7825643279. The next prime is 7825643281. The reversal of 7825643280 is 823465287.

7825643280 is a `hidden beast` number, since 7 + 8 + 2 + 564 + 3 + 2 + 80 = 666.

It is an interprime number because it is at equal distance from previous prime (7825643279) and next prime (7825643281).

It is a super-2 number, since 2×7825643280² (a number of 21 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7825643281) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 13562352 + ... + 13562928.

Almost surely, 2^7825643280 is an apocalyptic number.

7825643280 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7825643280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17483380992).

7825643280 is an abundant number, since it is smaller than the sum of its proper divisors (27141118704).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7825643280 is a wasteful number, since it uses less digits than its factorization.

7825643280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 645 (or 630 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 45.

The square root of 7825643280 is about 88462.6660235831. Note that the first 3 decimals coincide. The cubic root of 7825643280 is about 1985.3634198936.

The spelling of 7825643280 in words is "seven billion, eight hundred twenty-five million, six hundred forty-three thousand, two hundred eighty".