261213125 has 10 divisors (see below), whose sum is σ = 326412702. Its totient is φ = 208970000.

The previous prime is 261213103. The next prime is 261213133. The reversal of 261213125 is 521312162.

It can be written as a sum of positive squares in 5 ways, for example, as 26234884 + 234978241 = 5122^2 + 15329^2 .

It is not a de Polignac number, because 261213125 - 2⁶ = 261213061 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 261213125.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 208346 + ... + 209595.

Almost surely, 2^261213125 is an apocalyptic number.

261213125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

261213125 is a deficient number, since it is larger than the sum of its proper divisors (65199577).

261213125 is an frugal number, since it uses more digits than its factorization.

261213125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417961 (or 417946 counting only the distinct ones).

The product of its digits is 720, while the sum is 23.

The square root of 261213125 is about 16162.0891285749. The cubic root of 261213125 is about 639.2415535266.

Adding to 261213125 its reverse (521312162), we get a palindrome (782525287).

The spelling of 261213125 in words is "two hundred sixty-one million, two hundred thirteen thousand, one hundred twenty-five".