21220144200 has 72 divisors (see below), whose sum is σ = 71264323650. Its totient is φ = 5658704640.

The previous prime is 21220144193. The next prime is 21220144223. The reversal of 21220144200 is 244102212.

21220144200 is a `hidden beast` number, since 2 + 1 + 220 + 1 + 442 + 0 + 0 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 15938052516 + 5282091684 = 126246^2 + 72678^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 5892685 + ... + 5896284.

Almost surely, 2^21220144200 is an apocalyptic number.

21220144200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21220144200 is an abundant number, since it is smaller than the sum of its proper divisors (50044179450).

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

21220144200 is a wasteful number, since it uses less digits than its factorization.

21220144200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11788991 (or 11788979 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

Adding to 21220144200 its reverse (244102212), we get a palindrome (21464246412).

The spelling of 21220144200 in words is "twenty-one billion, two hundred twenty million, one hundred forty-four thousand, two hundred".