11505780225 has 27 divisors (see below), whose sum is σ = 20611013059. Its totient is φ = 6135558000.

The previous prime is 11505780203. The next prime is 11505780233. The reversal of 11505780225 is 52208750511.

The square root of 11505780225 is 107265.

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

11505780225 is a `hidden beast` number, since 11 + 50 + 578 + 0 + 2 + 25 = 666.

It can be written as a sum of positive squares in only one way, i.e., 4142080881 + 7363699344 = 64359^2 + 85812^2 .

It is not a de Polignac number, because 11505780225 - 2⁹ = 11505779713 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 11505780225.

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, 1605400 + ... + 1612550.

Almost surely, 2^11505780225 is an apocalyptic number.

11505780225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

11505780225 is the 107265-th square number.

11505780225 is the 53633-rd centered octagonal number.

It is an amenable number.

11505780225 is a deficient number, since it is larger than the sum of its proper divisors (9105232834).

11505780225 is an frugal number, since it uses more digits than its factorization.

11505780225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14318 (or 7159 counting only the distinct ones).

The product of its (nonzero) digits is 28000, while the sum is 36.

Multiplying 11505780225 by its sum of digits (36), we get a square (414208088100 = 643590²).

The spelling of 11505780225 in words is "eleven billion, five hundred five million, seven hundred eighty thousand, two hundred twenty-five".