261688315 has 32 divisors (see below), whose sum is σ = 372833280. Its totient is φ = 172523904.

The previous prime is 261688291. The next prime is 261688331. The reversal of 261688315 is 513886162.

It is not a de Polignac number, because 261688315 - 2¹⁷ = 261557243 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 351834 + ... + 352576.

It is an arithmetic number, because the mean of its divisors is an integer number (11651040).

Almost surely, 2^261688315 is an apocalyptic number.

261688315 is a deficient number, since it is larger than the sum of its proper divisors (111144965).

261688315 is a wasteful number, since it uses less digits than its factorization.

261688315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1131.

The product of its digits is 69120, while the sum is 40.

The square root of 261688315 is about 16176.7832092787. The cubic root of 261688315 is about 639.6289475143.

The spelling of 261688315 in words is "two hundred sixty-one million, six hundred eighty-eight thousand, three hundred fifteen".