64643523 has 32 divisors (see below), whose sum is σ = 102643200. Its totient is φ = 35406336.

The previous prime is 64643519. The next prime is 64643531. The reversal of 64643523 is 32534646.

It is not a de Polignac number, because 64643523 - 2² = 64643519 is a prime.

It is not an unprimeable number, because it can be changed into a prime (64643563) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 108715 + ... + 109307.

It is an arithmetic number, because the mean of its divisors is an integer number (3207600).

Almost surely, 2^64643523 is an apocalyptic number.

64643523 is a deficient number, since it is larger than the sum of its proper divisors (37999677).

64643523 is a wasteful number, since it uses less digits than its factorization.

64643523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 811.

The product of its digits is 51840, while the sum is 33.

The square root of 64643523 is about 8040.1195886628. The cubic root of 64643523 is about 401.3362043413.

The spelling of 64643523 in words is "sixty-four million, six hundred forty-three thousand, five hundred twenty-three".