172109157 has 8 divisors (see below), whose sum is σ = 250340640. Its totient is φ = 104308560.

The previous prime is 172109153. The next prime is 172109167. The reversal of 172109157 is 751901271.

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

It is not a de Polignac number, because 172109157 - 2² = 172109153 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 5215429 = 172109157 / (1 + 7 + 2 + 1 + 0 + 9 + 1 + 5 + 7).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172109153) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2607682 + ... + 2607747.

It is an arithmetic number, because the mean of its divisors is an integer number (31292580).

Almost surely, 2^172109157 is an apocalyptic number.

It is an amenable number.

172109157 is a deficient number, since it is larger than the sum of its proper divisors (78231483).

172109157 is a wasteful number, since it uses less digits than its factorization.

172109157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5215443.

The product of its (nonzero) digits is 4410, while the sum is 33.

The square root of 172109157 is about 13119.0379601555. The cubic root of 172109157 is about 556.2473980100.

The spelling of 172109157 in words is "one hundred seventy-two million, one hundred nine thousand, one hundred fifty-seven".