261957779 has 2 divisors, whose sum is σ = 261957780. Its totient is φ = 261957778.

The previous prime is 261957767. The next prime is 261957791. The reversal of 261957779 is 977759162.

It is a balanced prime because it is at equal distance from previous prime (261957767) and next prime (261957791).

It is a cyclic number.

It is not a de Polignac number, because 261957779 - 2²⁴ = 245180563 is a prime.

It is a super-2 number, since 2×261957779² = 137243755957225682, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 261957779.

It is not a weakly prime, because it can be changed into another prime (261957749) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130978889 + 130978890.

It is an arithmetic number, because the mean of its divisors is an integer number (130978890).

Almost surely, 2^261957779 is an apocalyptic number.

261957779 is a deficient number, since it is larger than the sum of its proper divisors (1).

261957779 is an equidigital number, since it uses as much as digits as its factorization.

261957779 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1666980, while the sum is 53.

The square root of 261957779 is about 16185.1097926458. The cubic root of 261957779 is about 639.8484170629.

The spelling of 261957779 in words is "two hundred sixty-one million, nine hundred fifty-seven thousand, seven hundred seventy-nine".