64687531 has 2 divisors, whose sum is σ = 64687532. Its totient is φ = 64687530.

The previous prime is 64687529. The next prime is 64687543. The reversal of 64687531 is 13578646.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 64687531 - 2¹ = 64687529 is a prime.

It is a super-2 number, since 2×64687531² = 8368953333751922, which contains 22 as substring.

Together with 64687529, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (64687561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32343765 + 32343766.

It is an arithmetic number, because the mean of its divisors is an integer number (32343766).

Almost surely, 2^64687531 is an apocalyptic number.

64687531 is a deficient number, since it is larger than the sum of its proper divisors (1).

64687531 is an equidigital number, since it uses as much as digits as its factorization.

64687531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120960, while the sum is 40.

The square root of 64687531 is about 8042.8558982491. The cubic root of 64687531 is about 401.4272575327.

The spelling of 64687531 in words is "sixty-four million, six hundred eighty-seven thousand, five hundred thirty-one".