1620756864 has 160 divisors (see below), whose sum is σ = 4851887040. Its totient is φ = 537062400.

The previous prime is 1620756827. The next prime is 1620756899. The reversal of 1620756864 is 4686570261.

1620756864 is a `hidden beast` number, since 1 + 6 + 20 + 7 + 568 + 64 = 666.

It is a super-2 number, since 2×1620756864² = 5253705624406228992, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2311714 + ... + 2312414.

It is an arithmetic number, because the mean of its divisors is an integer number (30324294).

Almost surely, 2^1620756864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1620756864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2425943520).

1620756864 is an abundant number, since it is smaller than the sum of its proper divisors (3231130176).

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

1620756864 is an equidigital number, since it uses as much as digits as its factorization.

1620756864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 950 (or 929 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 45.

The square root of 1620756864 is about 40258.6247157053. The cubic root of 1620756864 is about 1174.6431664902.

The spelling of 1620756864 in words is "one billion, six hundred twenty million, seven hundred fifty-six thousand, eight hundred sixty-four".