2261561777 has 2 divisors, whose sum is σ = 2261561778. Its totient is φ = 2261561776.

The previous prime is 2261561759. The next prime is 2261561807. The reversal of 2261561777 is 7771651622.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2085840241 + 175721536 = 45671^2 + 13256^2 .

It is a cyclic number.

It is not a de Polignac number, because 2261561777 - 2⁸ = 2261561521 is a prime.

It is a super-2 number, since 2×2261561777² = 10229323342374795458, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2261561747) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1130780888 + 1130780889.

It is an arithmetic number, because the mean of its divisors is an integer number (1130780889).

Almost surely, 2^2261561777 is an apocalyptic number.

It is an amenable number.

2261561777 is a deficient number, since it is larger than the sum of its proper divisors (1).

2261561777 is an equidigital number, since it uses as much as digits as its factorization.

2261561777 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 246960, while the sum is 44.

The square root of 2261561777 is about 47555.8805722279. The cubic root of 2261561777 is about 1312.6113396946.

The spelling of 2261561777 in words is "two billion, two hundred sixty-one million, five hundred sixty-one thousand, seven hundred seventy-seven".