64491831 has 18 divisors (see below), whose sum is σ = 94982888. Its totient is φ = 42166800.

The previous prime is 64491799. The next prime is 64491877. The reversal of 64491831 is 13819446.

64491831 is a `hidden beast` number, since 644 + 9 + 1 + 8 + 3 + 1 = 666.

64491831 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 64491831 - 2⁵ = 64491799 is a prime.

It is a super-2 number, since 2×64491831² = 8318392531465122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64491881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 24006 + ... + 26556.

Almost surely, 2^64491831 is an apocalyptic number.

64491831 is a deficient number, since it is larger than the sum of its proper divisors (30491057).

64491831 is a wasteful number, since it uses less digits than its factorization.

64491831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2663 (or 2607 counting only the distinct ones).

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

The square root of 64491831 is about 8030.6806062749. The cubic root of 64491831 is about 401.0220343072.

The spelling of 64491831 in words is "sixty-four million, four hundred ninety-one thousand, eight hundred thirty-one".