21182910840 has 192 divisors, whose sum is σ = 84731774400. Its totient is φ = 4469354496.

The previous prime is 21182910797. The next prime is 21182910841. The reversal of 21182910840 is 4801928112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21182910795 and 21182910804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21182910841) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 290545 + ... + 356064.

It is an arithmetic number, because the mean of its divisors is an integer number (441311325).

Almost surely, 2^21182910840 is an apocalyptic number.

21182910840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21182910840 is an abundant number, since it is smaller than the sum of its proper divisors (63548863560).

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

21182910840 is a wasteful number, since it uses less digits than its factorization.

21182910840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 646646 (or 646639 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The spelling of 21182910840 in words is "twenty-one billion, one hundred eighty-two million, nine hundred ten thousand, eight hundred forty".