315720261 has 20 divisors (see below), whose sum is σ = 477611200. Its totient is φ = 207811656.

The previous prime is 315720257. The next prime is 315720263. The reversal of 315720261 is 162027513.

It is a happy number.

315720261 is a `hidden beast` number, since 31 + 572 + 0 + 2 + 61 = 666.

It is not a de Polignac number, because 315720261 - 2² = 315720257 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (315720263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 18271 + ... + 31068.

It is an arithmetic number, because the mean of its divisors is an integer number (23880560).

Almost surely, 2^315720261 is an apocalyptic number.

It is an amenable number.

315720261 is a deficient number, since it is larger than the sum of its proper divisors (161890939).

315720261 is an equidigital number, since it uses as much as digits as its factorization.

315720261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49430 (or 49421 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 27.

The square root of 315720261 is about 17768.5188184046. The cubic root of 315720261 is about 680.9274117744.

Adding to 315720261 its reverse (162027513), we get a palindrome (477747774).

The spelling of 315720261 in words is "three hundred fifteen million, seven hundred twenty thousand, two hundred sixty-one".