21087832 has 8 divisors (see below), whose sum is σ = 39539700. Its totient is φ = 10543912.

The previous prime is 21087827. The next prime is 21087841. The reversal of 21087832 is 23878012.

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 21087794 and 21087803.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1317982 + ... + 1317997.

Almost surely, 2^21087832 is an apocalyptic number.

It is an amenable number.

21087832 is a deficient number, since it is larger than the sum of its proper divisors (18451868).

21087832 is a wasteful number, since it uses less digits than its factorization.

21087832 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2635985 (or 2635981 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 21087832 is about 4592.1489522880. The cubic root of 21087832 is about 276.2765204571.

The spelling of 21087832 in words is "twenty-one million, eighty-seven thousand, eight hundred thirty-two".