261117213 has 16 divisors (see below), whose sum is σ = 398184960. Its totient is φ = 149100336.

The previous prime is 261117211. The next prime is 261117223. The reversal of 261117213 is 312711162.

261117213 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 261117213 - 2¹ = 261117211 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261117211) 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, 31278 + ... + 38736.

It is an arithmetic number, because the mean of its divisors is an integer number (24886560).

Almost surely, 2^261117213 is an apocalyptic number.

It is an amenable number.

261117213 is a deficient number, since it is larger than the sum of its proper divisors (137067747).

261117213 is a wasteful number, since it uses less digits than its factorization.

261117213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9136.

The product of its digits is 504, while the sum is 24.

The square root of 261117213 is about 16159.1216654866. The cubic root of 261117213 is about 639.1633052361.

Adding to 261117213 its reverse (312711162), we get a palindrome (573828375).

The spelling of 261117213 in words is "two hundred sixty-one million, one hundred seventeen thousand, two hundred thirteen".