64656091 has 4 divisors (see below), whose sum is σ = 64729872. Its totient is φ = 64582312.

The previous prime is 64656073. The next prime is 64656101. The reversal of 64656091 is 19065646.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19065646 = 2 ⋅9532823.

It is a cyclic number.

It is not a de Polignac number, because 64656091 - 2⁷ = 64655963 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 64656091.

It is not an unprimeable number, because it can be changed into a prime (64656041) 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, 35560 + ... + 37333.

It is an arithmetic number, because the mean of its divisors is an integer number (16182468).

Almost surely, 2^64656091 is an apocalyptic number.

64656091 is a deficient number, since it is larger than the sum of its proper divisors (73781).

64656091 is an equidigital number, since it uses as much as digits as its factorization.

64656091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73780.

The product of its (nonzero) digits is 38880, while the sum is 37.

The square root of 64656091 is about 8040.9011310922. The cubic root of 64656091 is about 401.3622119305.

The spelling of 64656091 in words is "sixty-four million, six hundred fifty-six thousand, ninety-one".