261539313 has 48 divisors (see below), whose sum is σ = 441864000. Its totient is φ = 136660608.

The previous prime is 261539309. The next prime is 261539321. The reversal of 261539313 is 313935162.

It is not a de Polignac number, because 261539313 - 2² = 261539309 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261539323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 79383 + ... + 82611.

It is an arithmetic number, because the mean of its divisors is an integer number (9205500).

Almost surely, 2^261539313 is an apocalyptic number.

It is an amenable number.

261539313 is a deficient number, since it is larger than the sum of its proper divisors (180324687).

261539313 is a wasteful number, since it uses less digits than its factorization.

261539313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3294 (or 3287 counting only the distinct ones).

The product of its digits is 14580, while the sum is 33.

The square root of 261539313 is about 16172.1771261633. The cubic root of 261539313 is about 639.5075256021.

The spelling of 261539313 in words is "two hundred sixty-one million, five hundred thirty-nine thousand, three hundred thirteen".