2127661681 has 2 divisors, whose sum is σ = 2127661682. Its totient is φ = 2127661680.

The previous prime is 2127661619. The next prime is 2127661699. The reversal of 2127661681 is 1861667212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1443316081 + 684345600 = 37991^2 + 26160^2 .

It is a cyclic number.

It is not a de Polignac number, because 2127661681 - 2¹⁷ = 2127530609 is a prime.

It is a super-2 number, since 2×2127661681² = 9053888457591491522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2127661181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1063830840 + 1063830841.

It is an arithmetic number, because the mean of its divisors is an integer number (1063830841).

Almost surely, 2^2127661681 is an apocalyptic number.

It is an amenable number.

2127661681 is a deficient number, since it is larger than the sum of its proper divisors (1).

2127661681 is an equidigital number, since it uses as much as digits as its factorization.

2127661681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48384, while the sum is 40.

The square root of 2127661681 is about 46126.5832357004. The cubic root of 2127661681 is about 1286.1773502996.

The spelling of 2127661681 in words is "two billion, one hundred twenty-seven million, six hundred sixty-one thousand, six hundred eighty-one".