261261516 has 12 divisors (see below), whose sum is σ = 609610232. Its totient is φ = 87087168.

The previous prime is 261261503. The next prime is 261261523. The reversal of 261261516 is 615162162.

It is a tau number, because it is divible by the number of its divisors (12).

It is a plaindrome in base 14.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10885885 + ... + 10885908.

Almost surely, 2^261261516 is an apocalyptic number.

It is an amenable number.

261261516 is an abundant number, since it is smaller than the sum of its proper divisors (348348716).

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

261261516 is a wasteful number, since it uses less digits than its factorization.

261261516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21771800 (or 21771798 counting only the distinct ones).

The product of its digits is 4320, while the sum is 30.

The square root of 261261516 is about 16163.5861119988. The cubic root of 261261516 is about 639.2810252900.

The spelling of 261261516 in words is "two hundred sixty-one million, two hundred sixty-one thousand, five hundred sixteen".