21480557808 has 240 divisors, whose sum is σ = 62870618880. Its totient is φ = 6285920256.

The previous prime is 21480557797. The next prime is 21480557867. The reversal of 21480557808 is 80875508412.

It is a super-2 number, since 2×21480557808² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

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, 34701723 + ... + 34702341.

It is an arithmetic number, because the mean of its divisors is an integer number (261960912).

Almost surely, 2^21480557808 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 21480557808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31435309440).

21480557808 is an abundant number, since it is smaller than the sum of its proper divisors (41390061072).

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

21480557808 is a wasteful number, since it uses less digits than its factorization.

21480557808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 756 (or 707 counting only the distinct ones).

The product of its (nonzero) digits is 716800, while the sum is 48.

The spelling of 21480557808 in words is "twenty-one billion, four hundred eighty million, five hundred fifty-seven thousand, eight hundred eight".