21317932 has 24 divisors (see below), whose sum is σ = 39690000. Its totient is φ = 9984000.

The previous prime is 21317927. The next prime is 21317951. The reversal of 21317932 is 23971312.

It is a self number, because there is not a number n which added to its sum of digits gives 21317932.

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, 16444 + ... + 17692.

It is an arithmetic number, because the mean of its divisors is an integer number (1653750).

Almost surely, 2^21317932 is an apocalyptic number.

It is an amenable number.

21317932 is a deficient number, since it is larger than the sum of its proper divisors (18372068).

21317932 is a wasteful number, since it uses less digits than its factorization.

21317932 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1521 (or 1519 counting only the distinct ones).

The product of its digits is 2268, while the sum is 28.

The square root of 21317932 is about 4617.1346092571. The cubic root of 21317932 is about 277.2777518720.

It can be divided in two parts, 213 and 17932, that added together give a triangular number (18145 = T₁₉₀).

The spelling of 21317932 in words is "twenty-one million, three hundred seventeen thousand, nine hundred thirty-two".