265640531535961 has 2 divisors, whose sum is σ = 265640531535962. Its totient is φ = 265640531535960.

The previous prime is 265640531535949. The next prime is 265640531536067. The reversal of 265640531535961 is 169535135046562.

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., 216972900000000 + 48667631535961 = 14730000^2 + 6976219^2 .

It is a cyclic number.

It is not a de Polignac number, because 265640531535961 - 2²⁹ = 265639994665049 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 265640531535961.

It is not a weakly prime, because it can be changed into another prime (265640531535761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 132820265767980 + 132820265767981.

It is an arithmetic number, because the mean of its divisors is an integer number (132820265767981).

Almost surely, 2^{265640531535961} is an apocalyptic number.

It is an amenable number.

265640531535961 is a deficient number, since it is larger than the sum of its proper divisors (1).

265640531535961 is an equidigital number, since it uses as much as digits as its factorization.

265640531535961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 87480000, while the sum is 61.

The spelling of 265640531535961 in words is "two hundred sixty-five trillion, six hundred forty billion, five hundred thirty-one million, five hundred thirty-five thousand, nine hundred sixty-one".