261516613 has 4 divisors (see below), whose sum is σ = 262199808. Its totient is φ = 260833420.

The previous prime is 261516599. The next prime is 261516631. The reversal of 261516613 is 316615162.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 261516613 - 2¹⁷ = 261385541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261516653) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 341023 + ... + 341788.

It is an arithmetic number, because the mean of its divisors is an integer number (65549952).

Almost surely, 2^261516613 is an apocalyptic number.

It is an amenable number.

261516613 is a deficient number, since it is larger than the sum of its proper divisors (683195).

261516613 is an equidigital number, since it uses as much as digits as its factorization.

261516613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 683194.

The product of its digits is 6480, while the sum is 31.

The square root of 261516613 is about 16171.4752882970. The cubic root of 261516613 is about 639.4890232966.

The spelling of 261516613 in words is "two hundred sixty-one million, five hundred sixteen thousand, six hundred thirteen".