261665566162 has 128 divisors (see below), whose sum is σ = 537721970688. Its totient is φ = 92194502400.

The previous prime is 261665566133. The next prime is 261665566171.

261665566162 is nontrivially palindromic in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 96661213 + ... + 96663919.

It is an arithmetic number, because the mean of its divisors is an integer number (4200952896).

Almost surely, 2^261665566162 is an apocalyptic number.

261665566162 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

261665566162 is an abundant number, since it is smaller than the sum of its proper divisors (276056404526).

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

261665566162 is a wasteful number, since it uses less digits than its factorization.

261665566162 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3704.

The product of its digits is 4665600, while the sum is 52.

The spelling of 261665566162 in words is "two hundred sixty-one billion, six hundred sixty-five million, five hundred sixty-six thousand, one hundred sixty-two".