21294981184 has 189 divisors, whose sum is σ = 47780902533. Its totient is φ = 9414107136.

The previous prime is 21294981173. The next prime is 21294981217. The reversal of 21294981184 is 48118949212.

The square root of 21294981184 is 145928.

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

It can be written as a sum of positive squares in 13 ways, for example, as 2334784 + 21292646400 = 1528^2 + 145920^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 575540014 + ... + 575540050.

Almost surely, 2^21294981184 is an apocalyptic number.

21294981184 is the 145928-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21294981184

21294981184 is an abundant number, since it is smaller than the sum of its proper divisors (26485921349).

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

21294981184 is an equidigital number, since it uses as much as digits as its factorization.

21294981184 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178 (or 85 counting only the distinct ones).

The product of its digits is 331776, while the sum is 49.

Multiplying 21294981184 by its sum of digits (49), we get a square (1043454078016 = 1021496²).

The spelling of 21294981184 in words is "twenty-one billion, two hundred ninety-four million, nine hundred eighty-one thousand, one hundred eighty-four".