261516435787 has 2 divisors, whose sum is σ = 261516435788. Its totient is φ = 261516435786.

The previous prime is 261516435781. The next prime is 261516435821. The reversal of 261516435787 is 787534615162.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 261516435787 - 2¹⁹ = 261515911499 is a prime.

It is not a weakly prime, because it can be changed into another prime (261516435781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130758217893 + 130758217894.

It is an arithmetic number, because the mean of its divisors is an integer number (130758217894).

Almost surely, 2^261516435787 is an apocalyptic number.

261516435787 is a deficient number, since it is larger than the sum of its proper divisors (1).

261516435787 is an equidigital number, since it uses as much as digits as its factorization.

261516435787 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8467200, while the sum is 55.

The spelling of 261516435787 in words is "two hundred sixty-one billion, five hundred sixteen million, four hundred thirty-five thousand, seven hundred eighty-seven".