21716969400 has 768 divisors, whose sum is σ = 90508492800. Its totient is φ = 4681152000.

The previous prime is 21716969381. The next prime is 21716969419. The reversal of 21716969400 is 496961712.

21716969400 is a `hidden beast` number, since 21 + 7 + 169 + 69 + 400 = 666.

It is an interprime number because it is at equal distance from previous prime (21716969381) and next prime (21716969419).

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 pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 50387185 + ... + 50387615.

It is an arithmetic number, because the mean of its divisors is an integer number (117849600).

Almost surely, 2^21716969400 is an apocalyptic number.

21716969400 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 21716969400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45254246400).

21716969400 is an abundant number, since it is smaller than the sum of its proper divisors (68791523400).

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

21716969400 is a wasteful number, since it uses less digits than its factorization.

21716969400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 537 (or 522 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 45.

The spelling of 21716969400 in words is "twenty-one billion, seven hundred sixteen million, nine hundred sixty-nine thousand, four hundred".