172137905 has 8 divisors (see below), whose sum is σ = 210463272. Its totient is φ = 135111808.

The previous prime is 172137887. The next prime is 172137907. The reversal of 172137905 is 509731271.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 7862416 + 164275489 = 2804^2 + 12817^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 172137905 - 2⁶ = 172137841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (172137907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 324524 + ... + 325053.

It is an arithmetic number, because the mean of its divisors is an integer number (26307909).

Almost surely, 2^172137905 is an apocalyptic number.

It is an amenable number.

172137905 is a deficient number, since it is larger than the sum of its proper divisors (38325367).

172137905 is an equidigital number, since it uses as much as digits as its factorization.

172137905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 649635.

The product of its (nonzero) digits is 13230, while the sum is 35.

The square root of 172137905 is about 13120.1335740152. The cubic root of 172137905 is about 556.2783669412.

The spelling of 172137905 in words is "one hundred seventy-two million, one hundred thirty-seven thousand, nine hundred five".