21390266880 has 480 divisors, whose sum is σ = 78785403840. Its totient is φ = 5348229120.

The previous prime is 21390266851. The next prime is 21390266927. The reversal of 21390266880 is 8866209312.

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

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 47 ways as a sum of consecutive naturals, for example, 57346374 + ... + 57346746.

It is an arithmetic number, because the mean of its divisors is an integer number (164136258).

Almost surely, 2^21390266880 is an apocalyptic number.

21390266880 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 21390266880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39392701920).

21390266880 is an abundant number, since it is smaller than the sum of its proper divisors (57395136960).

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

21390266880 is a wasteful number, since it uses less digits than its factorization.

21390266880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 552 (or 533 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 45.

The spelling of 21390266880 in words is "twenty-one billion, three hundred ninety million, two hundred sixty-six thousand, eight hundred eighty".