261223525 has 12 divisors (see below), whose sum is σ = 324442404. Its totient is φ = 208640000.

The previous prime is 261223511. The next prime is 261223541. The reversal of 261223525 is 525322162.

It can be written as a sum of positive squares in 6 ways, for example, as 19918369 + 241305156 = 4463^2 + 15534^2 .

It is not a de Polignac number, because 261223525 - 2²⁵ = 227669093 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261223493 and 261223502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7875 + ... + 24175.

It is an arithmetic number, because the mean of its divisors is an integer number (27036867).

Almost surely, 2^261223525 is an apocalyptic number.

261223525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

261223525 is a deficient number, since it is larger than the sum of its proper divisors (63218879).

261223525 is a wasteful number, since it uses less digits than its factorization.

261223525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16952 (or 16947 counting only the distinct ones).

The product of its digits is 7200, while the sum is 28.

The square root of 261223525 is about 16162.4108659568. The cubic root of 261223525 is about 639.2500370512.

Adding to 261223525 its reverse (525322162), we get a palindrome (786545687).

The spelling of 261223525 in words is "two hundred sixty-one million, two hundred twenty-three thousand, five hundred twenty-five".