21893632 has 40 divisors (see below), whose sum is σ = 44525052. Its totient is φ = 10752000.

The previous prime is 21893629. The next prime is 21893633. The reversal of 21893632 is 23639812.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 21678336 + 215296 = 4656^2 + 464^2 .

It is a super-2 number, since 2×21893632² = 958662244302848, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21893633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30882 + ... + 31582.

Almost surely, 2^21893632 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21893632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22262526).

21893632 is an abundant number, since it is smaller than the sum of its proper divisors (22631420).

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

21893632 is an frugal number, since it uses more digits than its factorization.

21893632 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 780 (or 764 counting only the distinct ones).

The product of its digits is 15552, while the sum is 34.

The square root of 21893632 is about 4679.0631540940. The cubic root of 21893632 is about 279.7516164628.

The spelling of 21893632 in words is "twenty-one million, eight hundred ninety-three thousand, six hundred thirty-two".