18033961381 has 2 divisors, whose sum is σ = 18033961382. Its totient is φ = 18033961380.

The previous prime is 18033961327. The next prime is 18033961411. The reversal of 18033961381 is 18316933081.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17679957156 + 354004225 = 132966^2 + 18815^2 .

It is an emirp because it is prime and its reverse (18316933081) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18033961381 is a prime.

It is a super-2 number, since 2×18033961381² (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 (18033961081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9016980690 + 9016980691.

It is an arithmetic number, because the mean of its divisors is an integer number (9016980691).

Almost surely, 2^18033961381 is an apocalyptic number.

It is an amenable number.

18033961381 is a deficient number, since it is larger than the sum of its proper divisors (1).

18033961381 is an equidigital number, since it uses as much as digits as its factorization.

18033961381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 93312, while the sum is 43.

The spelling of 18033961381 in words is "eighteen billion, thirty-three million, nine hundred sixty-one thousand, three hundred eighty-one".