261715890427 has 2 divisors, whose sum is σ = 261715890428. Its totient is φ = 261715890426.

The previous prime is 261715890421. The next prime is 261715890493. The reversal of 261715890427 is 724098517162.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 261715890427 - 2⁷ = 261715890299 is a prime.

It is not a weakly prime, because it can be changed into another prime (261715890421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130857945213 + 130857945214.

It is an arithmetic number, because the mean of its divisors is an integer number (130857945214).

Almost surely, 2^261715890427 is an apocalyptic number.

261715890427 is a deficient number, since it is larger than the sum of its proper divisors (1).

261715890427 is an equidigital number, since it uses as much as digits as its factorization.

261715890427 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1693440, while the sum is 52.

The spelling of 261715890427 in words is "two hundred sixty-one billion, seven hundred fifteen million, eight hundred ninety thousand, four hundred twenty-seven".