21199669920 has 1344 divisors, whose sum is σ = 93286867968. Its totient is φ = 4478976000.

The previous prime is 21199669913. The next prime is 21199669979. The reversal of 21199669920 is 2996699112.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 223 ways as a sum of consecutive naturals, for example, 517065100 + ... + 517065140.

It is an arithmetic number, because the mean of its divisors is an integer number (69409872).

Almost surely, 2^21199669920 is an apocalyptic number.

21199669920 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 21199669920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46643433984).

21199669920 is an abundant number, since it is smaller than the sum of its proper divisors (72087198048).

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

21199669920 is a wasteful number, since it uses less digits than its factorization.

21199669920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129 (or 106 counting only the distinct ones).

The product of its (nonzero) digits is 944784, while the sum is 54.

The spelling of 21199669920 in words is "twenty-one billion, one hundred ninety-nine million, six hundred sixty-nine thousand, nine hundred twenty".