64116561 has 4 divisors (see below), whose sum is σ = 85488752. Its totient is φ = 42744372.

The previous prime is 64116529. The next prime is 64116589. The reversal of 64116561 is 16561146.

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 64116561 - 2⁵ = 64116529 is a prime.

It is a super-2 number, since 2×64116561² = 8221866788933442, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (64116511) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10686091 + ... + 10686096.

It is an arithmetic number, because the mean of its divisors is an integer number (21372188).

Almost surely, 2^64116561 is an apocalyptic number.

It is an amenable number.

64116561 is a deficient number, since it is larger than the sum of its proper divisors (21372191).

64116561 is a wasteful number, since it uses less digits than its factorization.

64116561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21372190.

The product of its digits is 4320, while the sum is 30.

The square root of 64116561 is about 8007.2817485087. The cubic root of 64116561 is about 400.2426881431.

The spelling of 64116561 in words is "sixty-four million, one hundred sixteen thousand, five hundred sixty-one".