21881232 has 40 divisors (see below), whose sum is σ = 62808480. Its totient is φ = 7293600.

The previous prime is 21881221. The next prime is 21881243. The reversal of 21881232 is 23218812.

It is an interprime number because it is at equal distance from previous prime (21881221) and next prime (21881243).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21881196 and 21881205.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 24894 + ... + 25757.

It is an arithmetic number, because the mean of its divisors is an integer number (1570212).

Almost surely, 2^21881232 is an apocalyptic number.

It is an amenable number.

21881232 is an abundant number, since it is smaller than the sum of its proper divisors (40927248).

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

21881232 is a wasteful number, since it uses less digits than its factorization.

21881232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50668 (or 50656 counting only the distinct ones).

The product of its digits is 1536, while the sum is 27.

The square root of 21881232 is about 4677.7379148473. The cubic root of 21881232 is about 279.6987917395.

The spelling of 21881232 in words is "twenty-one million, eight hundred eighty-one thousand, two hundred thirty-two".