64640600640 has 1120 divisors, whose sum is σ = 290601196800. Its totient is φ = 13247815680.

The previous prime is 64640600623. The next prime is 64640600693. The reversal of 64640600640 is 4600604646.

It is a happy number.

64640600640 is a `hidden beast` number, since 6 + 4 + 6 + 4 + 0 + 6 + 0 + 0 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (1120).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 64640600595 and 64640600604.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 885487644 + ... + 885487716.

Almost surely, 2^64640600640 is an apocalyptic number.

64640600640 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 64640600640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145300598400).

64640600640 is an abundant number, since it is smaller than the sum of its proper divisors (225960596160).

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

64640600640 is an equidigital number, since it uses as much as digits as its factorization.

64640600640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150 (or 101 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 36.

The spelling of 64640600640 in words is "sixty-four billion, six hundred forty million, six hundred thousand, six hundred forty".