64989561 has 32 divisors (see below), whose sum is σ = 107751168. Its totient is φ = 33926400.

The previous prime is 64989527. The next prime is 64989569. The reversal of 64989561 is 16598946.

It is not a de Polignac number, because 64989561 - 2⁶ = 64989497 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 64989561.

It is not an unprimeable number, because it can be changed into a prime (64989569) 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, 26395 + ... + 28751.

It is an arithmetic number, because the mean of its divisors is an integer number (3367224).

Almost surely, 2^64989561 is an apocalyptic number.

It is an amenable number.

64989561 is a deficient number, since it is larger than the sum of its proper divisors (42761607).

64989561 is a wasteful number, since it uses less digits than its factorization.

64989561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2481.

The product of its digits is 466560, while the sum is 48.

The square root of 64989561 is about 8061.6103230062. The cubic root of 64989561 is about 402.0510504213.

The spelling of 64989561 in words is "sixty-four million, nine hundred eighty-nine thousand, five hundred sixty-one".