21118482385225 has 81 divisors (see below), whose sum is σ = 27834684739069. Its totient is φ = 15893760601600.

The previous prime is 21118482385211. The next prime is 21118482385321. The reversal of 21118482385225 is 52258328481112.

The square root of 21118482385225 is 4595485.

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

It can be written as a sum of positive squares in 40 ways, for example, as 2604360122809 + 18514122262416 = 1613803^2 + 4302804^2 .

It is not a de Polignac number, because 21118482385225 - 2¹³ = 21118482377033 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 27320157939 + ... + 27320158711.

Almost surely, 2^{21118482385225} is an apocalyptic number.

21118482385225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21118482385225 is the 4595485-th square number.

21118482385225 is the 2297743-rd centered octagonal number.

It is an amenable number.

21118482385225 is a deficient number, since it is larger than the sum of its proper divisors (6716202353844).

21118482385225 is an frugal number, since it uses more digits than its factorization.

21118482385225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1696 (or 848 counting only the distinct ones).

The product of its digits is 2457600, while the sum is 52.

The spelling of 21118482385225 in words is "twenty-one trillion, one hundred eighteen billion, four hundred eighty-two million, three hundred eighty-five thousand, two hundred twenty-five".