188172540 has 72 divisors (see below), whose sum is σ = 571924080. Its totient is φ = 50079744.

The previous prime is 188172533. The next prime is 188172553. The reversal of 188172540 is 45271881.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 188172495 and 188172504.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 154012 + ... + 155228.

It is an arithmetic number, because the mean of its divisors is an integer number (7943390).

Almost surely, 2^188172540 is an apocalyptic number.

188172540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

188172540 is an abundant number, since it is smaller than the sum of its proper divisors (383751540).

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

188172540 is a wasteful number, since it uses less digits than its factorization.

188172540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2091 (or 2086 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 36.

The square root of 188172540 is about 13717.5996442526. The cubic root of 188172540 is about 573.0406301425.

The spelling of 188172540 in words is "one hundred eighty-eight million, one hundred seventy-two thousand, five hundred forty".