261954225 has 81 divisors (see below), whose sum is σ = 514251777. Its totient is φ = 127408320.

The previous prime is 261954193. The next prime is 261954229. The reversal of 261954225 is 522459162.

The square root of 261954225 is 16185.

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 67519089 + 194435136 = 8217^2 + 13944^2 .

It is not a de Polignac number, because 261954225 - 2⁵ = 261954193 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 261954225.

It is not an unprimeable number, because it can be changed into a prime (261954229) 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, 3156034 + ... + 3156116.

Almost surely, 2^261954225 is an apocalyptic number.

261954225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

261954225 is the 16185-th square number.

261954225 is the 8093-rd centered octagonal number.

It is an amenable number.

261954225 is a deficient number, since it is larger than the sum of its proper divisors (252297552).

261954225 is a wasteful number, since it uses less digits than its factorization.

261954225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208 (or 104 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The cubic root of 261954225 is about 639.8455234267.

Multiplying 261954225 by its sum of digits (36), we get a square (9430352100 = 97110²).

The spelling of 261954225 in words is "two hundred sixty-one million, nine hundred fifty-four thousand, two hundred twenty-five".