18994564357 has 2 divisors, whose sum is σ = 18994564358. Its totient is φ = 18994564356.

The previous prime is 18994564331. The next prime is 18994564363. The reversal of 18994564357 is 75346549981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15868188961 + 3126375396 = 125969^2 + 55914^2 .

It is an emirp because it is prime and its reverse (75346549981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18994564357 - 2²³ = 18986175749 is a prime.

It is a super-2 number, since 2×18994564357² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18994564295 and 18994564304.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18994564307) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9497282178 + 9497282179.

It is an arithmetic number, because the mean of its divisors is an integer number (9497282179).

Almost surely, 2^18994564357 is an apocalyptic number.

It is an amenable number.

18994564357 is a deficient number, since it is larger than the sum of its proper divisors (1).

18994564357 is an equidigital number, since it uses as much as digits as its factorization.

18994564357 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32659200, while the sum is 61.

The spelling of 18994564357 in words is "eighteen billion, nine hundred ninety-four million, five hundred sixty-four thousand, three hundred fifty-seven".