187532721 has 6 divisors (see below), whose sum is σ = 270880610. Its totient is φ = 125021808.

The previous prime is 187532713. The next prime is 187532747. The reversal of 187532721 is 127235781.

187532721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 164865600 + 22667121 = 12840^2 + 4761^2 .

It is not a de Polignac number, because 187532721 - 2³ = 187532713 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (187532711) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10418476 + ... + 10418493.

Almost surely, 2^187532721 is an apocalyptic number.

It is an amenable number.

187532721 is a deficient number, since it is larger than the sum of its proper divisors (83347889).

187532721 is a wasteful number, since it uses less digits than its factorization.

187532721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20836975 (or 20836972 counting only the distinct ones).

The product of its digits is 23520, while the sum is 36.

The square root of 187532721 is about 13694.2586874938. The cubic root of 187532721 is about 572.3904137354.

It can be divided in two parts, 1875 and 32721, that added together give a square (34596 = 186²).

The spelling of 187532721 in words is "one hundred eighty-seven million, five hundred thirty-two thousand, seven hundred twenty-one".