173149921 has 4 divisors (see below), whose sum is σ = 197885632. Its totient is φ = 148414212.

The previous prime is 173149891. The next prime is 173149931. The reversal of 173149921 is 129941371.

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, and also an emirpimes, since its reverse is a distinct semiprime: 129941371 = 7 ⋅18563053.

It is a cyclic number.

It is not a de Polignac number, because 173149921 - 2²¹ = 171052769 is a prime.

It is not an unprimeable number, because it can be changed into a prime (173149931) 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, 12367845 + ... + 12367858.

It is an arithmetic number, because the mean of its divisors is an integer number (49471408).

Almost surely, 2^173149921 is an apocalyptic number.

It is an amenable number.

173149921 is a deficient number, since it is larger than the sum of its proper divisors (24735711).

173149921 is an equidigital number, since it uses as much as digits as its factorization.

173149921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24735710.

The product of its digits is 13608, while the sum is 37.

The square root of 173149921 is about 13158.6443450684. The cubic root of 173149921 is about 557.3663763083.

The spelling of 173149921 in words is "one hundred seventy-three million, one hundred forty-nine thousand, nine hundred twenty-one".