172421115 has 16 divisors (see below), whose sum is σ = 276622368. Its totient is φ = 91708416.

The previous prime is 172421111. The next prime is 172421131. The reversal of 172421115 is 511124271.

It is not a de Polignac number, because 172421115 - 2² = 172421111 is a prime.

It is not an unprimeable number, because it can be changed into a prime (172421111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9814 + ... + 21003.

It is an arithmetic number, because the mean of its divisors is an integer number (17288898).

Almost surely, 2^172421115 is an apocalyptic number.

172421115 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

172421115 is a deficient number, since it is larger than the sum of its proper divisors (104201253).

172421115 is a wasteful number, since it uses less digits than its factorization.

172421115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31198.

The product of its digits is 560, while the sum is 24.

The square root of 172421115 is about 13130.9220925265. The cubic root of 172421115 is about 556.5832722352.

Adding to 172421115 its reverse (511124271), we get a palindrome (683545386).

The spelling of 172421115 in words is "one hundred seventy-two million, four hundred twenty-one thousand, one hundred fifteen".