21871624320 has 768 divisors, whose sum is σ = 97089148800. Its totient is φ = 4612349952.

The previous prime is 21871624309. The next prime is 21871624351. The reversal of 21871624320 is 2342617812.

It is a happy number.

21871624320 is a `hidden beast` number, since 2 + 1 + 8 + 7 + 1 + 624 + 3 + 20 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 11006367 + ... + 11008353.

Almost surely, 2^21871624320 is an apocalyptic number.

21871624320 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 21871624320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48544574400).

21871624320 is an abundant number, since it is smaller than the sum of its proper divisors (75217524480).

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

21871624320 is a wasteful number, since it uses less digits than its factorization.

21871624320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2042 (or 2017 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The spelling of 21871624320 in words is "twenty-one billion, eight hundred seventy-one million, six hundred twenty-four thousand, three hundred twenty".