64692561 has 4 divisors (see below), whose sum is σ = 86256752. Its totient is φ = 43128372.

The previous prime is 64692559. The next prime is 64692571. The reversal of 64692561 is 16529646.

64692561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 64692561 - 2¹ = 64692559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64692541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10782091 + ... + 10782096.

It is an arithmetic number, because the mean of its divisors is an integer number (21564188).

Almost surely, 2^64692561 is an apocalyptic number.

It is an amenable number.

64692561 is a deficient number, since it is larger than the sum of its proper divisors (21564191).

64692561 is a wasteful number, since it uses less digits than its factorization.

64692561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21564190.

The product of its digits is 77760, while the sum is 39.

The square root of 64692561 is about 8043.1685920413. The cubic root of 64692561 is about 401.4376620457.

The spelling of 64692561 in words is "sixty-four million, six hundred ninety-two thousand, five hundred sixty-one".