172393905 has 16 divisors (see below), whose sum is σ = 279155520. Its totient is φ = 90835008.

The previous prime is 172393891. The next prime is 172393931. The reversal of 172393905 is 509393271.

It is not a de Polignac number, because 172393905 - 2⁵ = 172393873 is a prime.

It is a super-2 number, since 2×172393905² = 59439316962298050, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 67990 + ... + 70479.

It is an arithmetic number, because the mean of its divisors is an integer number (17447220).

Almost surely, 2^172393905 is an apocalyptic number.

172393905 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

172393905 is a deficient number, since it is larger than the sum of its proper divisors (106761615).

172393905 is a wasteful number, since it uses less digits than its factorization.

172393905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138560.

The product of its (nonzero) digits is 51030, while the sum is 39.

The square root of 172393905 is about 13129.8859477149. The cubic root of 172393905 is about 556.5539923187.

The spelling of 172393905 in words is "one hundred seventy-two million, three hundred ninety-three thousand, nine hundred five".