21731532 has 24 divisors (see below), whose sum is σ = 50862000. Its totient is φ = 7221696.

The previous prime is 21731519. The next prime is 21731533. The reversal of 21731532 is 23513712.

It is not an unprimeable number, because it can be changed into a prime (21731533) 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, 1594 + ... + 6782.

It is an arithmetic number, because the mean of its divisors is an integer number (2119250).

Almost surely, 2^21731532 is an apocalyptic number.

It is an amenable number.

21731532 is an abundant number, since it is smaller than the sum of its proper divisors (29130468).

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

21731532 is a wasteful number, since it uses less digits than its factorization.

21731532 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5545 (or 5543 counting only the distinct ones).

The product of its digits is 1260, while the sum is 24.

The square root of 21731532 is about 4661.7091286351. The cubic root of 21731532 is about 279.0594803876.

The spelling of 21731532 in words is "twenty-one million, seven hundred thirty-one thousand, five hundred thirty-two".