166115531 has 4 divisors (see below), whose sum is σ = 169649952. Its totient is φ = 162581112.

The previous prime is 166115513. The next prime is 166115549. The reversal of 166115531 is 135511661.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (166115513) and next prime (166115549).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166115531 is a prime.

It is a super-2 number, since 2×166115531² = 55188739278823922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 166115494 and 166115503.

It is not an unprimeable number, because it can be changed into a prime (166115581) 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, 1767140 + ... + 1767233.

It is an arithmetic number, because the mean of its divisors is an integer number (42412488).

Almost surely, 2^166115531 is an apocalyptic number.

166115531 is a deficient number, since it is larger than the sum of its proper divisors (3534421).

166115531 is an equidigital number, since it uses as much as digits as its factorization.

166115531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3534420.

The product of its digits is 2700, while the sum is 29.

The square root of 166115531 is about 12888.5814192253. The cubic root of 166115531 is about 549.7139349847.

The spelling of 166115531 in words is "one hundred sixty-six million, one hundred fifteen thousand, five hundred thirty-one".