66931 has 2 divisors, whose sum is σ = 66932. Its totient is φ = 66930.

The previous prime is 66923. The next prime is 66943. The reversal of 66931 is 13966.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66931 - 2³ = 66923 is a prime.

It is a super-2 number, since 2×66931² = 8959517522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66896 and 66905.

It is not a weakly prime, because it can be changed into another prime (66431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33465 + 33466.

It is an arithmetic number, because the mean of its divisors is an integer number (33466).

2⁶⁶⁹³¹ is an apocalyptic number.

66931 is a deficient number, since it is larger than the sum of its proper divisors (1).

66931 is an equidigital number, since it uses as much as digits as its factorization.

66931 is an evil number, because the sum of its binary digits is even.

The product of its digits is 972, while the sum is 25.

The square root of 66931 is about 258.7102626492. The cubic root of 66931 is about 40.6015335876.

The spelling of 66931 in words is "sixty-six thousand, nine hundred thirty-one".