172121768 has 64 divisors (see below), whose sum is σ = 399840000. Its totient is φ = 68043456.

The previous prime is 172121767. The next prime is 172121771. The reversal of 172121768 is 867121271.

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (172121767) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 122333 + ... + 123731.

It is an arithmetic number, because the mean of its divisors is an integer number (6247500).

Almost surely, 2^172121768 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 172121768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (199920000).

172121768 is an abundant number, since it is smaller than the sum of its proper divisors (227718232).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

172121768 is a wasteful number, since it uses less digits than its factorization.

172121768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1451 (or 1421 counting only the distinct ones).

The product of its digits is 9408, while the sum is 35.

The square root of 172121768 is about 13119.5185887288. The cubic root of 172121768 is about 556.2609836993.

The spelling of 172121768 in words is "one hundred seventy-two million, one hundred twenty-one thousand, seven hundred sixty-eight".