21598605604900 has 81 divisors (see below), whose sum is σ = 47682881213779. Its totient is φ = 8491932813760.

The previous prime is 21598605604897. The next prime is 21598605604921. The reversal of 21598605604900 is 940650689512.

The square root of 21598605604900 is 4647430.

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

It can be written as a sum of positive squares in 4 ways, for example, as 5449395347236 + 16149210257664 = 2334394^2 + 4018608^2 .

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, 2741979762 + ... + 2741987638.

Almost surely, 2^{21598605604900} is an apocalyptic number.

21598605604900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

21598605604900 is the 4647430-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21598605604900

21598605604900 is an abundant number, since it is smaller than the sum of its proper divisors (26084275608879).

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

21598605604900 is an frugal number, since it uses more digits than its factorization.

21598605604900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15886 (or 7943 counting only the distinct ones).

The product of its (nonzero) digits is 4665600, while the sum is 55.

The spelling of 21598605604900 in words is "twenty-one trillion, five hundred ninety-eight billion, six hundred five million, six hundred four thousand, nine hundred".