18331737121 has 2 divisors, whose sum is σ = 18331737122. Its totient is φ = 18331737120.

The previous prime is 18331737119. The next prime is 18331737133. The reversal of 18331737121 is 12173713381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18295267600 + 36469521 = 135260^2 + 6039^2 .

It is a cyclic number.

It is not a de Polignac number, because 18331737121 - 2¹ = 18331737119 is a prime.

Together with 18331737119, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (18331732121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9165868560 + 9165868561.

It is an arithmetic number, because the mean of its divisors is an integer number (9165868561).

Almost surely, 2^18331737121 is an apocalyptic number.

It is an amenable number.

18331737121 is a deficient number, since it is larger than the sum of its proper divisors (1).

18331737121 is an equidigital number, since it uses as much as digits as its factorization.

18331737121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21168, while the sum is 37.

The spelling of 18331737121 in words is "eighteen billion, three hundred thirty-one million, seven hundred thirty-seven thousand, one hundred twenty-one".