65520864 has 72 divisors (see below), whose sum is σ = 188638632. Its totient is φ = 21569280.

The previous prime is 65520853. The next prime is 65520869. The reversal of 65520864 is 46802556.

It is a tau number, because it is divible by the number of its divisors (72).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65520869) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22534 + ... + 25274.

It is an arithmetic number, because the mean of its divisors is an integer number (2619981).

Almost surely, 2^65520864 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 65520864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94319316).

65520864 is an abundant number, since it is smaller than the sum of its proper divisors (123117768).

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

65520864 is a wasteful number, since it uses less digits than its factorization.

65520864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2840 (or 2829 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The square root of 65520864 is about 8094.4959077141. The cubic root of 65520864 is about 403.1436948965.

The spelling of 65520864 in words is "sixty-five million, five hundred twenty thousand, eight hundred sixty-four".