20610909225 has 81 divisors (see below), whose sum is σ = 39285500293. Its totient is φ = 10327491840.

The previous prime is 20610909199. The next prime is 20610909227. The reversal of 20610909225 is 52290901602.

It is a happy number.

The square root of 20610909225 is 143565.

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 482109849 + 20128799376 = 21957^2 + 141876^2 .

It is not a de Polignac number, because 20610909225 - 2¹⁵ = 20610876457 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20610909225.

It is not an unprimeable number, because it can be changed into a prime (20610909227) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 36608794 + ... + 36609356.

Almost surely, 2^20610909225 is an apocalyptic number.

20610909225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20610909225 is the 143565-th square number.

20610909225 is the 71783-rd centered octagonal number.

It is an amenable number.

20610909225 is a deficient number, since it is larger than the sum of its proper divisors (18674591068).

20610909225 is an equidigital number, since it uses as much as digits as its factorization.

20610909225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1176 (or 588 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

Multiplying 20610909225 by its sum of digits (36), we get a square (741992732100 = 861390²).

The spelling of 20610909225 in words is "twenty billion, six hundred ten million, nine hundred nine thousand, two hundred twenty-five".