166957987 has 8 divisors (see below), whose sum is σ = 190944000. Its totient is φ = 143005704.

The previous prime is 166957979. The next prime is 166958021. The reversal of 166957987 is 789759661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 166957987 - 2³ = 166957979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166957937) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3264 + ... + 18562.

It is an arithmetic number, because the mean of its divisors is an integer number (23868000).

Almost surely, 2^166957987 is an apocalyptic number.

166957987 is a deficient number, since it is larger than the sum of its proper divisors (23986013).

166957987 is a wasteful number, since it uses less digits than its factorization.

166957987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16865.

The product of its digits is 5715360, while the sum is 58.

The square root of 166957987 is about 12921.2223492981. Note that the first 3 decimals coincide. The cubic root of 166957987 is about 550.6416610283.

The spelling of 166957987 in words is "one hundred sixty-six million, nine hundred fifty-seven thousand, nine hundred eighty-seven".