18620136973 has 2 divisors, whose sum is σ = 18620136974. Its totient is φ = 18620136972.

The previous prime is 18620136961. The next prime is 18620136991. The reversal of 18620136973 is 37963102681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17145807364 + 1474329609 = 130942^2 + 38397^2 .

It is a cyclic number.

It is not a de Polignac number, because 18620136973 - 2⁹ = 18620136461 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18620136943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9310068486 + 9310068487.

It is an arithmetic number, because the mean of its divisors is an integer number (9310068487).

Almost surely, 2^18620136973 is an apocalyptic number.

It is an amenable number.

18620136973 is a deficient number, since it is larger than the sum of its proper divisors (1).

18620136973 is an equidigital number, since it uses as much as digits as its factorization.

18620136973 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 326592, while the sum is 46.

The spelling of 18620136973 in words is "eighteen billion, six hundred twenty million, one hundred thirty-six thousand, nine hundred seventy-three".