64694891 has 4 divisors (see below), whose sum is σ = 64722984. Its totient is φ = 64666800.

The previous prime is 64694813. The next prime is 64694933. The reversal of 64694891 is 19849646.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19849646 = 2 ⋅9924823.

It is a cyclic number.

It is not a de Polignac number, because 64694891 - 2¹⁸ = 64432747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64694801) 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, 10250 + ... + 15311.

It is an arithmetic number, because the mean of its divisors is an integer number (16180746).

Almost surely, 2^64694891 is an apocalyptic number.

64694891 is a deficient number, since it is larger than the sum of its proper divisors (28093).

64694891 is a wasteful number, since it uses less digits than its factorization.

64694891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28092.

The product of its digits is 373248, while the sum is 47.

The square root of 64694891 is about 8043.3134341514. The cubic root of 64694891 is about 401.4424814485.

The spelling of 64694891 in words is "sixty-four million, six hundred ninety-four thousand, eight hundred ninety-one".