2136643661 has 2 divisors, whose sum is σ = 2136643662. Its totient is φ = 2136643660.

The previous prime is 2136643631. The next prime is 2136643687. The reversal of 2136643661 is 1663466312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1703212900 + 433430761 = 41270^2 + 20819^2 .

It is a cyclic number.

It is not a de Polignac number, because 2136643661 - 2¹⁴ = 2136627277 is a prime.

It is a super-2 number, since 2×2136643661² = 9130492268182965842, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2136643631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1068321830 + 1068321831.

It is an arithmetic number, because the mean of its divisors is an integer number (1068321831).

Almost surely, 2^2136643661 is an apocalyptic number.

It is an amenable number.

2136643661 is a deficient number, since it is larger than the sum of its proper divisors (1).

2136643661 is an equidigital number, since it uses as much as digits as its factorization.

2136643661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 93312, while the sum is 38.

The square root of 2136643661 is about 46223.8429925509. The cubic root of 2136643661 is about 1287.9846866629.

The spelling of 2136643661 in words is "two billion, one hundred thirty-six million, six hundred forty-three thousand, six hundred sixty-one".