21984732 has 162 divisors, whose sum is σ = 71746584. Its totient is φ = 5654880.

The previous prime is 21984727. The next prime is 21984737. The reversal of 21984732 is 23748912.

It is an interprime number because it is at equal distance from previous prime (21984727) and next prime (21984737).

It is a super-2 number, since 2×21984732² = 966656882223648, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

Its product of digits (24192) is a multiple of the sum of its prime divisors (126).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21984737) by changing a digit.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 213393 + ... + 213495.

Almost surely, 2^21984732 is an apocalyptic number.

21984732 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21984732, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35873292).

21984732 is an abundant number, since it is smaller than the sum of its proper divisors (49761852).

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

21984732 is a wasteful number, since it uses less digits than its factorization.

21984732 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149 (or 126 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 21984732 is about 4688.7879030726. The cubic root of 21984732 is about 280.1390975548.

The spelling of 21984732 in words is "twenty-one million, nine hundred eighty-four thousand, seven hundred thirty-two".