166953921 has 4 divisors (see below), whose sum is σ = 222605232. Its totient is φ = 111302612.

The previous prime is 166953877. The next prime is 166953937. The reversal of 166953921 is 129359661.

166953921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 166953921 - 2¹⁰ = 166952897 is a prime.

It is a super-2 number, since 2×166953921² = 55747223474548482, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (166952921) 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, 27825651 + ... + 27825656.

It is an arithmetic number, because the mean of its divisors is an integer number (55651308).

Almost surely, 2^166953921 is an apocalyptic number.

It is an amenable number.

166953921 is a deficient number, since it is larger than the sum of its proper divisors (55651311).

166953921 is an equidigital number, since it uses as much as digits as its factorization.

166953921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55651310.

The product of its digits is 87480, while the sum is 42.

The square root of 166953921 is about 12921.0650102846. The cubic root of 166953921 is about 550.6371909872.

The spelling of 166953921 in words is "one hundred sixty-six million, nine hundred fifty-three thousand, nine hundred twenty-one".