21491132 has 24 divisors (see below), whose sum is σ = 41080032. Its totient is φ = 9777600.

The previous prime is 21491101. The next prime is 21491149. The reversal of 21491132 is 23119412.

It is a junction number, because it is equal to n+sod(n) for n = 21491098 and 21491107.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 782 + ... + 6602.

It is an arithmetic number, because the mean of its divisors is an integer number (1711668).

Almost surely, 2^21491132 is an apocalyptic number.

It is an amenable number.

21491132 is a deficient number, since it is larger than the sum of its proper divisors (19588900).

21491132 is a wasteful number, since it uses less digits than its factorization.

21491132 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5909 (or 5907 counting only the distinct ones).

The product of its digits is 432, while the sum is 23.

The square root of 21491132 is about 4635.8528880887. The cubic root of 21491132 is about 278.0266523797.

The spelling of 21491132 in words is "twenty-one million, four hundred ninety-one thousand, one hundred thirty-two".