21210622680 has 128 divisors (see below), whose sum is σ = 68669798400. Its totient is φ = 5210168832.

The previous prime is 21210622651. The next prime is 21210622687. The reversal of 21210622680 is 8622601212.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210622687) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 745761 + ... + 773679.

It is an arithmetic number, because the mean of its divisors is an integer number (536482800).

Almost surely, 2^21210622680 is an apocalyptic number.

21210622680 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 21210622680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34334899200).

21210622680 is an abundant number, since it is smaller than the sum of its proper divisors (47459175720).

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

21210622680 is a wasteful number, since it uses less digits than its factorization.

21210622680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28433 (or 28429 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The spelling of 21210622680 in words is "twenty-one billion, two hundred ten million, six hundred twenty-two thousand, six hundred eighty".