261311201677 has 2 divisors, whose sum is σ = 261311201678. Its totient is φ = 261311201676.

The previous prime is 261311201623. The next prime is 261311201687. The reversal of 261311201677 is 776102113162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 203391078121 + 57920123556 = 450989^2 + 240666^2 .

It is a cyclic number.

It is not a de Polignac number, because 261311201677 - 2²³ = 261302813069 is a prime.

It is a super-2 number, since 2×261311201677² (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 (261311201687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130655600838 + 130655600839.

It is an arithmetic number, because the mean of its divisors is an integer number (130655600839).

Almost surely, 2^261311201677 is an apocalyptic number.

It is an amenable number.

261311201677 is a deficient number, since it is larger than the sum of its proper divisors (1).

261311201677 is an equidigital number, since it uses as much as digits as its factorization.

261311201677 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21168, while the sum is 37.

The spelling of 261311201677 in words is "two hundred sixty-one billion, three hundred eleven million, two hundred one thousand, six hundred seventy-seven".