21224621880 has 384 divisors, whose sum is σ = 86215034880. Its totient is φ = 4399349760.

The previous prime is 21224621863. The next prime is 21224621909. The reversal of 21224621880 is 8812642212.

21224621880 is a `hidden beast` number, since 2 + 1 + 2 + 24 + 621 + 8 + 8 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 15993777 + ... + 15995103.

It is an arithmetic number, because the mean of its divisors is an integer number (224518320).

Almost surely, 2^21224621880 is an apocalyptic number.

21224621880 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 21224621880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43107517440).

21224621880 is an abundant number, since it is smaller than the sum of its proper divisors (64990413000).

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

21224621880 is a wasteful number, since it uses less digits than its factorization.

21224621880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1939 (or 1932 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 36.

The spelling of 21224621880 in words is "twenty-one billion, two hundred twenty-four million, six hundred twenty-one thousand, eight hundred eighty".