261252166488136 has 16 divisors (see below), whose sum is σ = 489849296975100. Its totient is φ = 130625687294784.

The previous prime is 261252166488127. The next prime is 261252166488139. The reversal of 261252166488136 is 631884661252162.

It can be written as a sum of positive squares in 2 ways, for example, as 259139486796100 + 2112679692036 = 16097810^2 + 1453506^2 .

It is not an unprimeable number, because it can be changed into a prime (261252166488139) 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, 46680051 + ... + 51976258.

Almost surely, 2^{261252166488136} is an apocalyptic number.

It is an amenable number.

261252166488136 is a deficient number, since it is larger than the sum of its proper divisors (228597130486964).

261252166488136 is a wasteful number, since it uses less digits than its factorization.

261252166488136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98987328 (or 98987324 counting only the distinct ones).

The product of its digits is 39813120, while the sum is 61.

The spelling of 261252166488136 in words is "two hundred sixty-one trillion, two hundred fifty-two billion, one hundred sixty-six million, four hundred eighty-eight thousand, one hundred thirty-six".