172151121 has 16 divisors (see below), whose sum is σ = 236674944. Its totient is φ = 111222144.

The previous prime is 172151117. The next prime is 172151131. The reversal of 172151121 is 121151271.

It is not a de Polignac number, because 172151121 - 2² = 172151117 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (172151131) 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 in 15 ways as a sum of consecutive naturals, for example, 26245 + ... + 32141.

It is an arithmetic number, because the mean of its divisors is an integer number (14792184).

Almost surely, 2^172151121 is an apocalyptic number.

It is an amenable number.

172151121 is a deficient number, since it is larger than the sum of its proper divisors (64523823).

172151121 is a wasteful number, since it uses less digits than its factorization.

172151121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6200.

The product of its digits is 140, while the sum is 21.

The square root of 172151121 is about 13120.6372177574. The cubic root of 172151121 is about 556.2926027884.

It can be divided in two parts, 17215 and 1121, that added together give a triangular number (18336 = T₁₉₁).

The spelling of 172151121 in words is "one hundred seventy-two million, one hundred fifty-one thousand, one hundred twenty-one".