65640645 has 48 divisors (see below), whose sum is σ = 135760320. Its totient is φ = 30004128.

The previous prime is 65640629. The next prime is 65640647. The reversal of 65640645 is 54604656.

It is a happy number.

65640645 is a `hidden beast` number, since 6 + 5 + 6 + 4 + 0 + 645 = 666.

It is not a de Polignac number, because 65640645 - 2⁴ = 65640629 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65640647) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1654 + ... + 11576.

It is an arithmetic number, because the mean of its divisors is an integer number (2828340).

Almost surely, 2^65640645 is an apocalyptic number.

It is an amenable number.

65640645 is an abundant number, since it is smaller than the sum of its proper divisors (70119675).

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

65640645 is a wasteful number, since it uses less digits than its factorization.

65640645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9951 (or 9938 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 36.

The square root of 65640645 is about 8101.8914458292. The cubic root of 65640645 is about 403.3892124084.

The spelling of 65640645 in words is "sixty-five million, six hundred forty thousand, six hundred forty-five".