21502879488 has 216 divisors, whose sum is σ = 68079696048. Its totient is φ = 6745669632.

The previous prime is 21502879483. The next prime is 21502879547. The reversal of 21502879488 is 88497820512.

21502879488 is a `hidden beast` number, since 2 + 150 + 2 + 8 + 7 + 9 + 488 = 666.

It is a tau number, because it is divible by the number of its divisors (216).

It is a super-2 number, since 2×21502879488² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21502879483) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1047370 + ... + 1067702.

It is an arithmetic number, because the mean of its divisors is an integer number (315183778).

Almost surely, 2^21502879488 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 21502879488, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34039848024).

21502879488 is an abundant number, since it is smaller than the sum of its proper divisors (46576816560).

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

21502879488 is an equidigital number, since it uses as much as digits as its factorization.

21502879488 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20381 (or 20355 counting only the distinct ones).

The product of its (nonzero) digits is 2580480, while the sum is 54.

The spelling of 21502879488 in words is "twenty-one billion, five hundred two million, eight hundred seventy-nine thousand, four hundred eighty-eight".