21219748900 has 81 divisors (see below), whose sum is σ = 53590461267. Its totient is φ = 7271846400.

The previous prime is 21219748897. The next prime is 21219748903. The reversal of 21219748900 is 984791212.

It is a happy number.

The square root of 21219748900 is 145670.

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

It is an interprime number because it is at equal distance from previous prime (21219748897) and next prime (21219748903).

It can be written as a sum of positive squares in 4 ways, for example, as 1446889444 + 19772859456 = 38038^2 + 140616^2 .

It is not an unprimeable number, because it can be changed into a prime (21219748903) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 10195860 + ... + 10197940.

Almost surely, 2^21219748900 is an apocalyptic number.

21219748900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

21219748900 is the 145670-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21219748900

21219748900 is an abundant number, since it is smaller than the sum of its proper divisors (32370712367).

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

21219748900 is an equidigital number, since it uses as much as digits as its factorization.

21219748900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4190 (or 2095 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 43.

The spelling of 21219748900 in words is "twenty-one billion, two hundred nineteen million, seven hundred forty-eight thousand, nine hundred".