172102391 has 16 divisors (see below), whose sum is σ = 180271104. Its totient is φ = 164182464.

The previous prime is 172102387. The next prime is 172102393. The reversal of 172102391 is 193201271.

It is a cyclic number.

It is not a de Polignac number, because 172102391 - 2² = 172102387 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 172102391.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172102393) 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 15 ways as a sum of consecutive naturals, for example, 353150 + ... + 353636.

It is an arithmetic number, because the mean of its divisors is an integer number (11266944).

Almost surely, 2^172102391 is an apocalyptic number.

172102391 is a deficient number, since it is larger than the sum of its proper divisors (8168713).

172102391 is a wasteful number, since it uses less digits than its factorization.

172102391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 710.

The product of its (nonzero) digits is 756, while the sum is 26.

The square root of 172102391 is about 13118.7800881027. The cubic root of 172102391 is about 556.2401088003.

The spelling of 172102391 in words is "one hundred seventy-two million, one hundred two thousand, three hundred ninety-one".