261625515 has 16 divisors (see below), whose sum is σ = 419078400. Its totient is φ = 139374432.

The previous prime is 261625493. The next prime is 261625519. The reversal of 261625515 is 515526162.

It is not a de Polignac number, because 261625515 - 2¹⁸ = 261363371 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261625519) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4296 + ... + 23274.

It is an arithmetic number, because the mean of its divisors is an integer number (26192400).

Almost surely, 2^261625515 is an apocalyptic number.

261625515 is a deficient number, since it is larger than the sum of its proper divisors (157452885).

261625515 is a wasteful number, since it uses less digits than its factorization.

261625515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19906.

The product of its digits is 18000, while the sum is 33.

The square root of 261625515 is about 16174.8420394142. The cubic root of 261625515 is about 639.5777773381.

The spelling of 261625515 in words is "two hundred sixty-one million, six hundred twenty-five thousand, five hundred fifteen".