166958921 has 8 divisors (see below), whose sum is σ = 176899104. Its totient is φ = 157032000.

The previous prime is 166958893. The next prime is 166958923. The reversal of 166958921 is 129859661.

It is a happy number.

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 166958921 - 2¹⁴ = 166942537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166958923) 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, 36086 + ... + 40448.

It is an arithmetic number, because the mean of its divisors is an integer number (22112388).

Almost surely, 2^166958921 is an apocalyptic number.

It is an amenable number.

166958921 is a deficient number, since it is larger than the sum of its proper divisors (9940183).

166958921 is a wasteful number, since it uses less digits than its factorization.

166958921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6631.

The product of its digits is 233280, while the sum is 47.

The square root of 166958921 is about 12921.2584913390. The cubic root of 166958921 is about 550.6426878302.

The spelling of 166958921 in words is "one hundred sixty-six million, nine hundred fifty-eight thousand, nine hundred twenty-one".