21437472 has 192 divisors, whose sum is σ = 71608320. Its totient is φ = 5474304.

The previous prime is 21437443. The next prime is 21437501. The reversal of 21437472 is 27473412.

It is an interprime number because it is at equal distance from previous prime (21437443) and next prime (21437501).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 293628 + ... + 293700.

It is an arithmetic number, because the mean of its divisors is an integer number (372960).

Almost surely, 2^21437472 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 21437472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35804160).

21437472 is an abundant number, since it is smaller than the sum of its proper divisors (50170848).

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

21437472 is a wasteful number, since it uses less digits than its factorization.

21437472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135 (or 127 counting only the distinct ones).

The product of its digits is 9408, while the sum is 30.

The square root of 21437472 is about 4630.0617706463. The cubic root of 21437472 is about 277.7950631495.

The spelling of 21437472 in words is "twenty-one million, four hundred thirty-seven thousand, four hundred seventy-two".