64520640 has 168 divisors, whose sum is σ = 227521008. Its totient is φ = 16773120.

The previous prime is 64520633. The next prime is 64520647. The reversal of 64520640 is 4602546.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (64520633) and next prime (64520647).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64520647) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 123580 + ... + 124100.

Almost surely, 2^64520640 is an apocalyptic number.

64520640 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 64520640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113760504).

64520640 is an abundant number, since it is smaller than the sum of its proper divisors (163000368).

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

64520640 is a wasteful number, since it uses less digits than its factorization.

64520640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 587 (or 574 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The square root of 64520640 is about 8032.4740895941. The cubic root of 64520640 is about 401.0817386334.

The spelling of 64520640 in words is "sixty-four million, five hundred twenty thousand, six hundred forty".