21158632 has 32 divisors (see below), whose sum is σ = 44776800. Its totient is φ = 9284800.

The previous prime is 21158563. The next prime is 21158633. The reversal of 21158632 is 23685112.

It is a super-2 number, since 2×21158632² = 895375416222848, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21158632.

It is not an unprimeable number, because it can be changed into a prime (21158633) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1594 + ... + 6697.

It is an arithmetic number, because the mean of its divisors is an integer number (1399275).

Almost surely, 2^21158632 is an apocalyptic number.

21158632 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21158632 is an abundant number, since it is smaller than the sum of its proper divisors (23618168).

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

21158632 is a wasteful number, since it uses less digits than its factorization.

21158632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8337 (or 8333 counting only the distinct ones).

The product of its digits is 2880, while the sum is 28.

The square root of 21158632 is about 4599.8513019444. The cubic root of 21158632 is about 276.5853640880.

The spelling of 21158632 in words is "twenty-one million, one hundred fifty-eight thousand, six hundred thirty-two".