64517891 has 8 divisors (see below), whose sum is σ = 65339568. Its totient is φ = 63700000.

The previous prime is 64517879. The next prime is 64517903. The reversal of 64517891 is 19871546.

It is an interprime number because it is at equal distance from previous prime (64517879) and next prime (64517903).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64517891 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64511891) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48941 + ... + 50241.

It is an arithmetic number, because the mean of its divisors is an integer number (8167446).

Almost surely, 2^64517891 is an apocalyptic number.

64517891 is a deficient number, since it is larger than the sum of its proper divisors (821677).

64517891 is a wasteful number, since it uses less digits than its factorization.

64517891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1893.

The product of its digits is 60480, while the sum is 41.

The square root of 64517891 is about 8032.3029698835. The cubic root of 64517891 is about 401.0760423200.

The spelling of 64517891 in words is "sixty-four million, five hundred seventeen thousand, eight hundred ninety-one".