18687891737 has 2 divisors, whose sum is σ = 18687891738. Its totient is φ = 18687891736.

The previous prime is 18687891721. The next prime is 18687891751. The reversal of 18687891737 is 73719878681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10236582976 + 8451308761 = 101176^2 + 91931^2 .

It is a cyclic number.

It is not a de Polignac number, because 18687891737 - 2⁴ = 18687891721 is a prime.

It is not a weakly prime, because it can be changed into another prime (18687891037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9343945868 + 9343945869.

It is an arithmetic number, because the mean of its divisors is an integer number (9343945869).

Almost surely, 2^18687891737 is an apocalyptic number.

It is an amenable number.

18687891737 is a deficient number, since it is larger than the sum of its proper divisors (1).

18687891737 is an equidigital number, since it uses as much as digits as its factorization.

18687891737 is an evil number, because the sum of its binary digits is even.

The product of its digits is 28449792, while the sum is 65.

The spelling of 18687891737 in words is "eighteen billion, six hundred eighty-seven million, eight hundred ninety-one thousand, seven hundred thirty-seven".