66651431 has 16 divisors (see below), whose sum is σ = 84157440. Its totient is φ = 51274080.

The previous prime is 66651427. The next prime is 66651433. The reversal of 66651431 is 13415666.

It is not a de Polignac number, because 66651431 - 2² = 66651427 is a prime.

It is a super-2 number, since 2×66651431² = 8884826508695522, 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 (66651433) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 605 + ... + 11561.

It is an arithmetic number, because the mean of its divisors is an integer number (5259840).

Almost surely, 2^66651431 is an apocalyptic number.

66651431 is a deficient number, since it is larger than the sum of its proper divisors (17506009).

66651431 is a wasteful number, since it uses less digits than its factorization.

66651431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11054.

The product of its digits is 12960, while the sum is 32.

The square root of 66651431 is about 8164.0327657353. The cubic root of 66651431 is about 405.4492418841.

The spelling of 66651431 in words is "sixty-six million, six hundred fifty-one thousand, four hundred thirty-one".