66437631 has 32 divisors (see below), whose sum is σ = 106659840. Its totient is φ = 40629600.

The previous prime is 66437627. The next prime is 66437633. The reversal of 66437631 is 13673466.

It is a happy number.

66437631 is a `hidden beast` number, since 6 + 643 + 7 + 6 + 3 + 1 = 666.

It is not a de Polignac number, because 66437631 - 2² = 66437627 is a prime.

It is a super-2 number, since 2×66437631² = 8827917625784322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66437633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 66546 + ... + 67536.

It is an arithmetic number, because the mean of its divisors is an integer number (3333120).

Almost surely, 2^66437631 is an apocalyptic number.

66437631 is a deficient number, since it is larger than the sum of its proper divisors (40222209).

66437631 is a wasteful number, since it uses less digits than its factorization.

66437631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1204 (or 1198 counting only the distinct ones).

The product of its digits is 54432, while the sum is 36.

The square root of 66437631 is about 8150.9282293491. The cubic root of 66437631 is about 405.0152531978.

The spelling of 66437631 in words is "sixty-six million, four hundred thirty-seven thousand, six hundred thirty-one".