64624561 has 4 divisors (see below), whose sum is σ = 64663792. Its totient is φ = 64585332.

The previous prime is 64624541. The next prime is 64624583. The reversal of 64624561 is 16542646.

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, and also an emirpimes, since its reverse is a distinct semiprime: 16542646 = 2 ⋅8271323.

It is a cyclic number.

It is not a de Polignac number, because 64624561 - 2⁷ = 64624433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64624541) 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, 17031 + ... + 20476.

It is an arithmetic number, because the mean of its divisors is an integer number (16165948).

Almost surely, 2^64624561 is an apocalyptic number.

It is an amenable number.

64624561 is a deficient number, since it is larger than the sum of its proper divisors (39231).

64624561 is a wasteful number, since it uses less digits than its factorization.

64624561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39230.

The product of its digits is 34560, while the sum is 34.

The square root of 64624561 is about 8038.9402908592. The cubic root of 64624561 is about 401.2969589487.

The spelling of 64624561 in words is "sixty-four million, six hundred twenty-four thousand, five hundred sixty-one".