64064640 has 128 divisors (see below), whose sum is σ = 207933120. Its totient is φ = 16773120.

The previous prime is 64064617. The next prime is 64064657. The reversal of 64064640 is 4646046.

64064640 = T₁₈₄ + T₁₈₅ + ... + T₇₃₀.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 64064598 and 64064607.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 116847 + ... + 117393.

Almost surely, 2^64064640 is an apocalyptic number.

64064640 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 64064640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103966560).

64064640 is an abundant number, since it is smaller than the sum of its proper divisors (143868480).

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

64064640 is a wasteful number, since it uses less digits than its factorization.

64064640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 630 (or 618 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 30.

The square root of 64064640 is about 8004.0389804148. The cubic root of 64064640 is about 400.1346213543.

The spelling of 64064640 in words is "sixty-four million, sixty-four thousand, six hundred forty".