64571891 has 2 divisors, whose sum is σ = 64571892. Its totient is φ = 64571890.

The previous prime is 64571887. The next prime is 64571909. The reversal of 64571891 is 19817546.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 64571891 - 2² = 64571887 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (64571851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32285945 + 32285946.

It is an arithmetic number, because the mean of its divisors is an integer number (32285946).

Almost surely, 2^64571891 is an apocalyptic number.

64571891 is a deficient number, since it is larger than the sum of its proper divisors (1).

64571891 is an equidigital number, since it uses as much as digits as its factorization.

64571891 is an evil number, because the sum of its binary digits is even.

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

The square root of 64571891 is about 8035.6636938090. The cubic root of 64571891 is about 401.1879082759.

The spelling of 64571891 in words is "sixty-four million, five hundred seventy-one thousand, eight hundred ninety-one".