2187636641 has 2 divisors, whose sum is σ = 2187636642. Its totient is φ = 2187636640.

The previous prime is 2187636599. The next prime is 2187636677. The reversal of 2187636641 is 1466367812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1210761616 + 976875025 = 34796^2 + 31255^2 .

It is a cyclic number.

It is not a de Polignac number, because 2187636641 - 2¹⁴ = 2187620257 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 2187636592 and 2187636601.

It is not a weakly prime, because it can be changed into another prime (2187636691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1093818320 + 1093818321.

It is an arithmetic number, because the mean of its divisors is an integer number (1093818321).

Almost surely, 2^2187636641 is an apocalyptic number.

It is an amenable number.

2187636641 is a deficient number, since it is larger than the sum of its proper divisors (1).

2187636641 is an equidigital number, since it uses as much as digits as its factorization.

2187636641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 290304, while the sum is 44.

The square root of 2187636641 is about 46772.1780655979. The cubic root of 2187636641 is about 1298.1505537605.

The spelling of 2187636641 in words is "two billion, one hundred eighty-seven million, six hundred thirty-six thousand, six hundred forty-one".