166987251 has 20 divisors (see below), whose sum is σ = 250164112. Its totient is φ = 111006288.

The previous prime is 166987231. The next prime is 166987279. The reversal of 166987251 is 152789661.

It is not a de Polignac number, because 166987251 - 2⁷ = 166987123 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 166987197 and 166987206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166987231) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 27450 + ... + 32976.

Almost surely, 2^166987251 is an apocalyptic number.

166987251 is a deficient number, since it is larger than the sum of its proper divisors (83176861).

166987251 is an equidigital number, since it uses as much as digits as its factorization.

166987251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5912 (or 5903 counting only the distinct ones).

The product of its digits is 181440, while the sum is 45.

The square root of 166987251 is about 12922.3547002859. The cubic root of 166987251 is about 550.6738308703.

The spelling of 166987251 in words is "one hundred sixty-six million, nine hundred eighty-seven thousand, two hundred fifty-one".