64513531 has 16 divisors (see below), whose sum is σ = 69483040. Its totient is φ = 59719680.

The previous prime is 64513517. The next prime is 64513549. The reversal of 64513531 is 13531546.

It is a 14-Lehmer number, since φ(64513531) divides (64513531-1)¹⁴.

It is a cyclic number.

It is not a de Polignac number, because 64513531 - 2⁵ = 64513499 is a prime.

It is a super-2 number, since 2×64513531² = 8323991364175922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 64513531.

It is not an unprimeable number, because it can be changed into a prime (64513571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 267571 + ... + 267811.

It is an arithmetic number, because the mean of its divisors is an integer number (4342690).

Almost surely, 2^64513531 is an apocalyptic number.

64513531 is a deficient number, since it is larger than the sum of its proper divisors (4969509).

64513531 is a wasteful number, since it uses less digits than its factorization.

64513531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 526.

The product of its digits is 5400, while the sum is 28.

The square root of 64513531 is about 8032.0315611930. The cubic root of 64513531 is about 401.0670074569.

The spelling of 64513531 in words is "sixty-four million, five hundred thirteen thousand, five hundred thirty-one".