166142921 has 16 divisors (see below), whose sum is σ = 201784320. Its totient is φ = 134003520.

The previous prime is 166142917. The next prime is 166142939. The reversal of 166142921 is 129241661.

It is not a de Polignac number, because 166142921 - 2² = 166142917 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166142941) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31976 + ... + 36806.

It is an arithmetic number, because the mean of its divisors is an integer number (12611520).

Almost surely, 2^166142921 is an apocalyptic number.

It is an amenable number.

166142921 is a deficient number, since it is larger than the sum of its proper divisors (35641399).

166142921 is an frugal number, since it uses more digits than its factorization.

166142921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4889 (or 4855 counting only the distinct ones).

The product of its digits is 5184, while the sum is 32.

The square root of 166142921 is about 12889.6439438799. The cubic root of 166142921 is about 549.7441465632.

The spelling of 166142921 in words is "one hundred sixty-six million, one hundred forty-two thousand, nine hundred twenty-one".