261015516 has 36 divisors (see below), whose sum is σ = 663225472. Its totient is φ = 86552064.

The previous prime is 261015511. The next prime is 261015527. The reversal of 261015516 is 615510162.

It is a happy number.

261015516 is a `hidden beast` number, since 2 + 6 + 101 + 551 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a self number, because there is not a number n which added to its sum of digits gives 261015516.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261015511) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11836 + ... + 25731.

Almost surely, 2^261015516 is an apocalyptic number.

It is an amenable number.

261015516 is an abundant number, since it is smaller than the sum of its proper divisors (402209956).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261015516 is a wasteful number, since it uses less digits than its factorization.

261015516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37770 (or 37765 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 27.

The square root of 261015516 is about 16155.9746224114. The cubic root of 261015516 is about 639.0803164124.

Adding to 261015516 its reverse (615510162), we get a palindrome (876525678).

The spelling of 261015516 in words is "two hundred sixty-one million, fifteen thousand, five hundred sixteen".