18551906184437 has 2 divisors, whose sum is σ = 18551906184438. Its totient is φ = 18551906184436.

The previous prime is 18551906184341. The next prime is 18551906184467. The reversal of 18551906184437 is 73448160915581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16600523491876 + 1951382692561 = 4074374^2 + 1396919^2 .

It is an emirp because it is prime and its reverse (73448160915581) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18551906184437 - 2⁸ = 18551906184181 is a prime.

It is a super-2 number, since 2×18551906184437² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 18551906184437.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18551906184467) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9275953092218 + 9275953092219.

It is an arithmetic number, because the mean of its divisors is an integer number (9275953092219).

Almost surely, 2^{18551906184437} is an apocalyptic number.

It is an amenable number.

18551906184437 is a deficient number, since it is larger than the sum of its proper divisors (1).

18551906184437 is an equidigital number, since it uses as much as digits as its factorization.

18551906184437 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 29030400, while the sum is 62.

The spelling of 18551906184437 in words is "eighteen trillion, five hundred fifty-one billion, nine hundred six million, one hundred eighty-four thousand, four hundred thirty-seven".