261622663161 has 8 divisors (see below), whose sum is σ = 348842348640. Its totient is φ = 174409043232.

The previous prime is 261622663067. The next prime is 261622663163. The reversal of 261622663161 is 161366226162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 261622663161 - 2¹⁴ = 261622646777 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261622663163) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1414771 + ... + 1588968.

It is an arithmetic number, because the mean of its divisors is an integer number (43605293580).

Almost surely, 2^261622663161 is an apocalyptic number.

It is an amenable number.

261622663161 is a deficient number, since it is larger than the sum of its proper divisors (87219685479).

261622663161 is a wasteful number, since it uses less digits than its factorization.

261622663161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3032775.

The product of its digits is 186624, while the sum is 42.

The spelling of 261622663161 in words is "two hundred sixty-one billion, six hundred twenty-two million, six hundred sixty-three thousand, one hundred sixty-one".