21532887 has 12 divisors (see below), whose sum is σ = 31182424. Its totient is φ = 14318640.

The previous prime is 21532873. The next prime is 21532891. The reversal of 21532887 is 78823512.

It is a de Polignac number, because none of the positive numbers 2^k-21532887 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21532837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 948 + ... + 6630.

Almost surely, 2^21532887 is an apocalyptic number.

21532887 is the 3789-th pentagonal number.

21532887 is a deficient number, since it is larger than the sum of its proper divisors (9649537).

21532887 is a wasteful number, since it uses less digits than its factorization.

21532887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6110 (or 6107 counting only the distinct ones).

The product of its digits is 26880, while the sum is 36.

The square root of 21532887 is about 4640.3541890679. The cubic root of 21532887 is about 278.2065947023.

The spelling of 21532887 in words is "twenty-one million, five hundred thirty-two thousand, eight hundred eighty-seven".