21861614880 has 480 divisors, whose sum is σ = 88542913536. Its totient is φ = 4976142336.

The previous prime is 21861614861. The next prime is 21861614923. The reversal of 21861614880 is 8841616812.

21861614880 is a `hidden beast` number, since 2 + 1 + 8 + 6 + 161 + 488 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

It is a super-2 number, since 2×21861614880² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 36015537 + ... + 36016143.

Almost surely, 2^21861614880 is an apocalyptic number.

21861614880 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 21861614880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44271456768).

21861614880 is an abundant number, since it is smaller than the sum of its proper divisors (66681298656).

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

21861614880 is a wasteful number, since it uses less digits than its factorization.

21861614880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1038 (or 1021 counting only the distinct ones).

The product of its (nonzero) digits is 147456, while the sum is 45.

The spelling of 21861614880 in words is "twenty-one billion, eight hundred sixty-one million, six hundred fourteen thousand, eight hundred eighty".