18962989781 has 2 divisors, whose sum is σ = 18962989782. Its totient is φ = 18962989780.

The previous prime is 18962989763. The next prime is 18962989807. The reversal of 18962989781 is 18798926981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10994571025 + 7968418756 = 104855^2 + 89266^2 .

It is a cyclic number.

It is not a de Polignac number, because 18962989781 - 2²⁶ = 18895880917 is a prime.

It is a super-2 number, since 2×18962989781² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18962989741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9481494890 + 9481494891.

It is an arithmetic number, because the mean of its divisors is an integer number (9481494891).

Almost surely, 2^18962989781 is an apocalyptic number.

It is an amenable number.

18962989781 is a deficient number, since it is larger than the sum of its proper divisors (1).

18962989781 is an equidigital number, since it uses as much as digits as its factorization.

18962989781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31352832, while the sum is 68.

The spelling of 18962989781 in words is "eighteen billion, nine hundred sixty-two million, nine hundred eighty-nine thousand, seven hundred eighty-one".