64816331 has 4 divisors (see below), whose sum is σ = 64955592. Its totient is φ = 64677072.

The previous prime is 64816327. The next prime is 64816333. The reversal of 64816331 is 13361846.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13361846 = 2 ⋅6680923.

It is a cyclic number.

It is not a de Polignac number, because 64816331 - 2² = 64816327 is a prime.

It is a super-2 number, since 2×64816331² = 8402313528603122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64816333) 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, 68930 + ... + 69863.

It is an arithmetic number, because the mean of its divisors is an integer number (16238898).

Almost surely, 2^64816331 is an apocalyptic number.

64816331 is a deficient number, since it is larger than the sum of its proper divisors (139261).

64816331 is a wasteful number, since it uses less digits than its factorization.

64816331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139260.

The product of its digits is 10368, while the sum is 32.

The square root of 64816331 is about 8050.8590224895. The cubic root of 64816331 is about 401.6935095284.

The spelling of 64816331 in words is "sixty-four million, eight hundred sixteen thousand, three hundred thirty-one".