21211009600 has 189 divisors, whose sum is σ = 57542282553. Its totient is φ = 7689792000.

The previous prime is 21211009579. The next prime is 21211009601. The reversal of 21211009600 is 690011212.

The square root of 21211009600 is 145640.

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

It can be written as a sum of positive squares in only one way, i.e., 7635963456 + 13575046144 = 87384^2 + 116512^2 .

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21211009601) 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, 64081435 + ... + 64081765.

Almost surely, 2^21211009600 is an apocalyptic number.

21211009600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

21211009600 is the 145640-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21211009600

21211009600 is an abundant number, since it is smaller than the sum of its proper divisors (36331272953).

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

21211009600 is an equidigital number, since it uses as much as digits as its factorization.

21211009600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 706 (or 349 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 22.

The spelling of 21211009600 in words is "twenty-one billion, two hundred eleven million, nine thousand, six hundred".