7826581645 has 4 divisors (see below), whose sum is σ = 9391897980. Its totient is φ = 6261265312.

The previous prime is 7826581643. The next prime is 7826581649. The reversal of 7826581645 is 5461856287.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4671175716 + 3155405929 = 68346^2 + 56173^2 .

It is a cyclic number.

It is not a de Polignac number, because 7826581645 - 2¹ = 7826581643 is a prime.

It is a super-3 number, since 3×7826581645³ (a number of 31 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 7826581592 and 7826581601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7826581643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 782658160 + ... + 782658169.

It is an arithmetic number, because the mean of its divisors is an integer number (2347974495).

Almost surely, 2^7826581645 is an apocalyptic number.

It is an amenable number.

7826581645 is a deficient number, since it is larger than the sum of its proper divisors (1565316335).

7826581645 is a wasteful number, since it uses less digits than its factorization.

7826581645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1565316334.

The product of its digits is 3225600, while the sum is 52.

The square root of 7826581645 is about 88467.9695991719. The cubic root of 7826581645 is about 1985.4427710311.

The spelling of 7826581645 in words is "seven billion, eight hundred twenty-six million, five hundred eighty-one thousand, six hundred forty-five".