172521240 has 64 divisors (see below), whose sum is σ = 521337600. Its totient is φ = 45670272.

The previous prime is 172521191. The next prime is 172521241. The reversal of 172521240 is 42125271.

It is a super-2 number, since 2×172521240² = 59527156502275200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 172521240.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172521241) 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, 11509 + ... + 21851.

It is an arithmetic number, because the mean of its divisors is an integer number (8145900).

Almost surely, 2^172521240 is an apocalyptic number.

172521240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 172521240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (260668800).

172521240 is an abundant number, since it is smaller than the sum of its proper divisors (348816360).

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

172521240 is a wasteful number, since it uses less digits than its factorization.

172521240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10496 (or 10492 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 24.

The square root of 172521240 is about 13134.7341046555. The cubic root of 172521240 is about 556.6909874195.

The spelling of 172521240 in words is "one hundred seventy-two million, five hundred twenty-one thousand, two hundred forty".