66731057 has 4 divisors (see below), whose sum is σ = 66848496. Its totient is φ = 66613620.

The previous prime is 66731051. The next prime is 66731083. The reversal of 66731057 is 75013766.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66731057 - 2¹⁴ = 66714673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66731051) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57863 + ... + 59004.

It is an arithmetic number, because the mean of its divisors is an integer number (16712124).

Almost surely, 2^66731057 is an apocalyptic number.

It is an amenable number.

66731057 is a deficient number, since it is larger than the sum of its proper divisors (117439).

66731057 is a wasteful number, since it uses less digits than its factorization.

66731057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117438.

The product of its (nonzero) digits is 26460, while the sum is 35.

The square root of 66731057 is about 8168.9079441502. The cubic root of 66731057 is about 405.6106360362.

The spelling of 66731057 in words is "sixty-six million, seven hundred thirty-one thousand, fifty-seven".