2801761661 has 2 divisors, whose sum is σ = 2801761662. Its totient is φ = 2801761660.

The previous prime is 2801761639. The next prime is 2801761667. The reversal of 2801761661 is 1661671082.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1858903225 + 942858436 = 43115^2 + 30706^2 .

It is a cyclic number.

It is not a de Polignac number, because 2801761661 - 2⁶ = 2801761597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2801761667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1400880830 + 1400880831.

It is an arithmetic number, because the mean of its divisors is an integer number (1400880831).

Almost surely, 2^2801761661 is an apocalyptic number.

It is an amenable number.

2801761661 is a deficient number, since it is larger than the sum of its proper divisors (1).

2801761661 is an equidigital number, since it uses as much as digits as its factorization.

2801761661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 2801761661 is about 52931.6697356129. The cubic root of 2801761661 is about 1409.7552785215.

The spelling of 2801761661 in words is "two billion, eight hundred one million, seven hundred sixty-one thousand, six hundred sixty-one".