261438225 has 12 divisors (see below), whose sum is σ = 432244656. Its totient is φ = 139433680.

The previous prime is 261438211. The next prime is 261438227. The reversal of 261438225 is 522834162.

It is not a de Polignac number, because 261438225 - 2⁴ = 261438209 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (261438227) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1742847 + ... + 1742996.

It is an arithmetic number, because the mean of its divisors is an integer number (36020388).

Almost surely, 2^261438225 is an apocalyptic number.

261438225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

261438225 is a deficient number, since it is larger than the sum of its proper divisors (170806431).

261438225 is a wasteful number, since it uses less digits than its factorization.

261438225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3485856 (or 3485851 counting only the distinct ones).

The product of its digits is 23040, while the sum is 33.

The square root of 261438225 is about 16169.0514564089. The cubic root of 261438225 is about 639.4251226080.

The spelling of 261438225 in words is "two hundred sixty-one million, four hundred thirty-eight thousand, two hundred twenty-five".