261053636381 has 2 divisors, whose sum is σ = 261053636382. Its totient is φ = 261053636380.

The previous prime is 261053636351. The next prime is 261053636447. The reversal of 261053636381 is 183636350162.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 188407215481 + 72646420900 = 434059^2 + 269530^2 .

It is a cyclic number.

It is not a de Polignac number, because 261053636381 - 2²² = 261049442077 is a prime.

It is a super-2 number, since 2×261053636381² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261053636351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130526818190 + 130526818191.

It is an arithmetic number, because the mean of its divisors is an integer number (130526818191).

Almost surely, 2^261053636381 is an apocalyptic number.

It is an amenable number.

261053636381 is a deficient number, since it is larger than the sum of its proper divisors (1).

261053636381 is an equidigital number, since it uses as much as digits as its factorization.

261053636381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 466560, while the sum is 44.

The spelling of 261053636381 in words is "two hundred sixty-one billion, fifty-three million, six hundred thirty-six thousand, three hundred eighty-one".