21872360 has 48 divisors (see below), whose sum is σ = 50940900. Its totient is φ = 8451840.

The previous prime is 21872341. The next prime is 21872369. The reversal of 21872360 is 6327812.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20484676 + 1387684 = 4526^2 + 1178^2 .

It is not an unprimeable number, because it can be changed into a prime (21872369) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 38156 + ... + 38724.

Almost surely, 2^21872360 is an apocalyptic number.

21872360 is a gapful number since it is divisible by the number (20) 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 21872360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25470450).

21872360 is an abundant number, since it is smaller than the sum of its proper divisors (29068540).

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

21872360 is a wasteful number, since it uses less digits than its factorization.

21872360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 642 (or 607 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 21872360 is about 4676.7894970802. The cubic root of 21872360 is about 279.6609842532.

The spelling of 21872360 in words is "twenty-one million, eight hundred seventy-two thousand, three hundred sixty".