21776904900 has 81 divisors (see below), whose sum is σ = 68272377901. Its totient is φ = 5805994080.

The previous prime is 21776904881. The next prime is 21776904911. The reversal of 21776904900 is 940967712.

The square root of 21776904900 is 147570.

It is a perfect power (a square), and thus also a powerful number.

21776904900 is a `hidden beast` number, since 2 + 1 + 7 + 76 + 90 + 490 + 0 = 666.

It can be written as a sum of positive squares in only one way, i.e., 7839685764 + 13937219136 = 88542^2 + 118056^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 4424641 + ... + 4429559.

Almost surely, 2^21776904900 is an apocalyptic number.

21776904900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

21776904900 is the 147570-th square number.

It is an amenable number.

21776904900 is an abundant number, since it is smaller than the sum of its proper divisors (46495473001).

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

21776904900 is an equidigital number, since it uses as much as digits as its factorization.

21776904900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9858 (or 4929 counting only the distinct ones).

The product of its (nonzero) digits is 190512, while the sum is 45.

The spelling of 21776904900 in words is "twenty-one billion, seven hundred seventy-six million, nine hundred four thousand, nine hundred".