21497374080 has 1536 divisors, whose sum is σ = 99800064000. Its totient is φ = 4389396480.

The previous prime is 21497374037. The next prime is 21497374091. The reversal of 21497374080 is 8047379412.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 693463665 + ... + 693463695.

It is an arithmetic number, because the mean of its divisors is an integer number (64974000).

Almost surely, 2^21497374080 is an apocalyptic number.

21497374080 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 21497374080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49900032000).

21497374080 is an abundant number, since it is smaller than the sum of its proper divisors (78302689920).

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

21497374080 is an equidigital number, since it uses as much as digits as its factorization.

21497374080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99 (or 61 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 45.

The spelling of 21497374080 in words is "twenty-one billion, four hundred ninety-seven million, three hundred seventy-four thousand, eighty".