18089980981 has 2 divisors, whose sum is σ = 18089980982. Its totient is φ = 18089980980.

The previous prime is 18089980939. The next prime is 18089981017. The reversal of 18089980981 is 18908998081.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16897660081 + 1192320900 = 129991^2 + 34530^2 .

It is an emirp because it is prime and its reverse (18908998081) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18089980981 - 2¹⁷ = 18089849909 is a prime.

It is a super-2 number, since 2×18089980981² (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 (18089980781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9044990490 + 9044990491.

It is an arithmetic number, because the mean of its divisors is an integer number (9044990491).

Almost surely, 2^18089980981 is an apocalyptic number.

It is an amenable number.

18089980981 is a deficient number, since it is larger than the sum of its proper divisors (1).

18089980981 is an equidigital number, since it uses as much as digits as its factorization.

18089980981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2985984, while the sum is 61.

The spelling of 18089980981 in words is "eighteen billion, eighty-nine million, nine hundred eighty thousand, nine hundred eighty-one".