261606615 has 16 divisors (see below), whose sum is σ = 420056448. Its totient is φ = 139028256.

The previous prime is 261606599. The next prime is 261606617. The reversal of 261606615 is 516606162.

It is not a de Polignac number, because 261606615 - 2⁴ = 261606599 is a prime.

It is a super-3 number, since 3×261606615³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261606617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26569 + ... + 35058.

It is an arithmetic number, because the mean of its divisors is an integer number (26253528).

Almost surely, 2^261606615 is an apocalyptic number.

261606615 is a deficient number, since it is larger than the sum of its proper divisors (158449833).

261606615 is a wasteful number, since it uses less digits than its factorization.

261606615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61918.

The product of its (nonzero) digits is 12960, while the sum is 33.

The square root of 261606615 is about 16174.2577882263. The cubic root of 261606615 is about 639.5623757936.

The spelling of 261606615 in words is "two hundred sixty-one million, six hundred six thousand, six hundred fifteen".