18949234981 has 2 divisors, whose sum is σ = 18949234982. Its totient is φ = 18949234980.

The previous prime is 18949234961. The next prime is 18949234987. The reversal of 18949234981 is 18943294981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18012324100 + 936910881 = 134210^2 + 30609^2 .

It is a cyclic number.

It is not a de Polignac number, because 18949234981 - 2⁷ = 18949234853 is a prime.

It is a super-2 number, since 2×18949234981² (a number of 21 digits) contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18949234987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9474617490 + 9474617491.

It is an arithmetic number, because the mean of its divisors is an integer number (9474617491).

Almost surely, 2^18949234981 is an apocalyptic number.

It is an amenable number.

18949234981 is a deficient number, since it is larger than the sum of its proper divisors (1).

18949234981 is an equidigital number, since it uses as much as digits as its factorization.

18949234981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4478976, while the sum is 58.

The spelling of 18949234981 in words is "eighteen billion, nine hundred forty-nine million, two hundred thirty-four thousand, nine hundred eighty-one".