21231532 has 12 divisors (see below), whose sum is σ = 42463120. Its totient is φ = 9099216.

The previous prime is 21231523. The next prime is 21231547. The reversal of 21231532 is 23513212.

21231532 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 379107 + ... + 379162.

It is a self-describing number.

Almost surely, 2^21231532 is an apocalyptic number.

It is an amenable number.

21231532 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21231532 is a wasteful number, since it uses less digits than its factorization.

21231532 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 758280 (or 758278 counting only the distinct ones).

The product of its digits is 360, while the sum is 19.

The square root of 21231532 is about 4607.7686573872. The cubic root of 21231532 is about 276.9026492608.

Adding to 21231532 its reverse (23513212), we get a palindrome (44744744).

It can be divided in two parts, 2123 and 1532, that added together give a triangular number (3655 = T₈₅).

The spelling of 21231532 in words is "twenty-one million, two hundred thirty-one thousand, five hundred thirty-two".