16181643637 has 2 divisors, whose sum is σ = 16181643638. Its totient is φ = 16181643636.

The previous prime is 16181643539. The next prime is 16181643649. The reversal of 16181643637 is 73634618161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11026260036 + 5155383601 = 105006^2 + 71801^2 .

It is a cyclic number.

It is not a de Polignac number, because 16181643637 - 2²⁷ = 16047425909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16181643697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8090821818 + 8090821819.

It is an arithmetic number, because the mean of its divisors is an integer number (8090821819).

Almost surely, 2^16181643637 is an apocalyptic number.

It is an amenable number.

16181643637 is a deficient number, since it is larger than the sum of its proper divisors (1).

16181643637 is an equidigital number, since it uses as much as digits as its factorization.

16181643637 is an evil number, because the sum of its binary digits is even.

The product of its digits is 435456, while the sum is 46.

The spelling of 16181643637 in words is "sixteen billion, one hundred eighty-one million, six hundred forty-three thousand, six hundred thirty-seven".