18937914661 has 2 divisors, whose sum is σ = 18937914662. Its totient is φ = 18937914660.

The previous prime is 18937914607. The next prime is 18937914679. The reversal of 18937914661 is 16641973981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17363332900 + 1574581761 = 131770^2 + 39681^2 .

It is a cyclic number.

It is not a de Polignac number, because 18937914661 - 2⁷ = 18937914533 is a prime.

It is a super-2 number, since 2×18937914661² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18937914361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9468957330 + 9468957331.

It is an arithmetic number, because the mean of its divisors is an integer number (9468957331).

Almost surely, 2^18937914661 is an apocalyptic number.

It is an amenable number.

18937914661 is a deficient number, since it is larger than the sum of its proper divisors (1).

18937914661 is an equidigital number, since it uses as much as digits as its factorization.

18937914661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1959552, while the sum is 55.

The spelling of 18937914661 in words is "eighteen billion, nine hundred thirty-seven million, nine hundred fourteen thousand, six hundred sixty-one".