172151906 has 4 divisors (see below), whose sum is σ = 258227862. Its totient is φ = 86075952.

The previous prime is 172151879. The next prime is 172151909. The reversal of 172151906 is 609151271.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 171741025 + 410881 = 13105^2 + 641^2 .

It is not an unprimeable number, because it can be changed into a prime (172151909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43037975 + ... + 43037978.

Almost surely, 2^172151906 is an apocalyptic number.

172151906 is a deficient number, since it is larger than the sum of its proper divisors (86075956).

172151906 is an equidigital number, since it uses as much as digits as its factorization.

172151906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86075955.

The product of its (nonzero) digits is 3780, while the sum is 32.

The square root of 172151906 is about 13120.6671324289. The cubic root of 172151906 is about 556.2934483421.

The spelling of 172151906 in words is "one hundred seventy-two million, one hundred fifty-one thousand, nine hundred six".