166231531 has 2 divisors, whose sum is σ = 166231532. Its totient is φ = 166231530.

The previous prime is 166231459. The next prime is 166231537. The reversal of 166231531 is 135132661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 166231531 - 2¹⁵ = 166198763 is a prime.

It is a super-2 number, since 2×166231531² = 55265843797207922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 166231531.

It is not a weakly prime, because it can be changed into another prime (166231537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83115765 + 83115766.

It is an arithmetic number, because the mean of its divisors is an integer number (83115766).

Almost surely, 2^166231531 is an apocalyptic number.

166231531 is a deficient number, since it is larger than the sum of its proper divisors (1).

166231531 is an equidigital number, since it uses as much as digits as its factorization.

166231531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3240, while the sum is 28.

The square root of 166231531 is about 12893.0807412348. The cubic root of 166231531 is about 549.8418619739.

The spelling of 166231531 in words is "one hundred sixty-six million, two hundred thirty-one thousand, five hundred thirty-one".