645349320 has 384 divisors, whose sum is σ = 2702868480. Its totient is φ = 129600000.

The previous prime is 645349279. The next prime is 645349321. The reversal of 645349320 is 23943546.

645349320 is a `hidden beast` number, since 645 + 3 + 4 + 9 + 3 + 2 + 0 = 666.

It is a hoax number, since the sum of its digits (36) 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 (36).

It is not an unprimeable number, because it can be changed into a prime (645349321) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 858945 + ... + 859695.

It is an arithmetic number, because the mean of its divisors is an integer number (7038720).

Almost surely, 2^645349320 is an apocalyptic number.

645349320 is a gapful number since it is divisible by the number (60) 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 645349320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1351434240).

645349320 is an abundant number, since it is smaller than the sum of its proper divisors (2057519160).

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

645349320 is a wasteful number, since it uses less digits than its factorization.

645349320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 817 (or 810 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 36.

The square root of 645349320 is about 25403.7264982915. The cubic root of 645349320 is about 864.1682092765.

The spelling of 645349320 in words is "six hundred forty-five million, three hundred forty-nine thousand, three hundred twenty".