21066972400 has 30 divisors (see below), whose sum is σ = 50613402152. Its totient is φ = 8426788800.

The previous prime is 21066972397. The next prime is 21066972401. The reversal of 21066972400 is 427966012.

It is a super-2 number, since 2×21066972400² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21066972400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21066972401) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 26333316 + ... + 26334115.

Almost surely, 2^21066972400 is an apocalyptic number.

21066972400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21066972400 is an abundant number, since it is smaller than the sum of its proper divisors (29546429752).

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

21066972400 is a wasteful number, since it uses less digits than its factorization.

21066972400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52667449 (or 52667438 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 37.

The spelling of 21066972400 in words is "twenty-one billion, sixty-six million, nine hundred seventy-two thousand, four hundred".