66974431 has 2 divisors, whose sum is σ = 66974432. Its totient is φ = 66974430.

The previous prime is 66974429. The next prime is 66974437. The reversal of 66974431 is 13447966.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66974431 - 2¹ = 66974429 is a prime.

It is a super-2 number, since 2×66974431² = 8971148815547522, which contains 22 as substring.

Together with 66974429, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66974437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33487215 + 33487216.

It is an arithmetic number, because the mean of its divisors is an integer number (33487216).

Almost surely, 2^66974431 is an apocalyptic number.

66974431 is a deficient number, since it is larger than the sum of its proper divisors (1).

66974431 is an equidigital number, since it uses as much as digits as its factorization.

66974431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108864, while the sum is 40.

The square root of 66974431 is about 8183.7907475692. The cubic root of 66974431 is about 406.1031369417.

The spelling of 66974431 in words is "sixty-six million, nine hundred seventy-four thousand, four hundred thirty-one".