261166379399 has 2 divisors, whose sum is σ = 261166379400. Its totient is φ = 261166379398.

The previous prime is 261166379381. The next prime is 261166379447. The reversal of 261166379399 is 993973661162.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 261166379399 - 2²⁴ = 261149602183 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261166379099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130583189699 + 130583189700.

It is an arithmetic number, because the mean of its divisors is an integer number (130583189700).

Almost surely, 2^261166379399 is an apocalyptic number.

261166379399 is a deficient number, since it is larger than the sum of its proper divisors (1).

261166379399 is an equidigital number, since it uses as much as digits as its factorization.

261166379399 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19840464, while the sum is 62.

The spelling of 261166379399 in words is "two hundred sixty-one billion, one hundred sixty-six million, three hundred seventy-nine thousand, three hundred ninety-nine".