64891431 has 24 divisors (see below), whose sum is σ = 108270864. Its totient is φ = 37013760.

The previous prime is 64891427. The next prime is 64891433. The reversal of 64891431 is 13419846.

64891431 is a `hidden beast` number, since 648 + 9 + 1 + 4 + 3 + 1 = 666.

It is not a de Polignac number, because 64891431 - 2² = 64891427 is a prime.

It is a super-2 number, since 2×64891431² = 8421795634455522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64891433) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17596 + ... + 20961.

It is an arithmetic number, because the mean of its divisors is an integer number (4511286).

Almost surely, 2^64891431 is an apocalyptic number.

64891431 is a deficient number, since it is larger than the sum of its proper divisors (43379433).

64891431 is a wasteful number, since it uses less digits than its factorization.

64891431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38591 (or 38588 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 64891431 is about 8055.5217708104. The cubic root of 64891431 is about 401.8485915293.

The spelling of 64891431 in words is "sixty-four million, eight hundred ninety-one thousand, four hundred thirty-one".