18498321451021 has 2 divisors, whose sum is σ = 18498321451022. Its totient is φ = 18498321451020.

The previous prime is 18498321451003. The next prime is 18498321451061. The reversal of 18498321451021 is 12015412389481.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17063392977796 + 1434928473225 = 4130786^2 + 1197885^2 .

It is a cyclic number.

It is not a de Polignac number, because 18498321451021 - 2¹⁵ = 18498321418253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18498321451061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9249160725510 + 9249160725511.

It is an arithmetic number, because the mean of its divisors is an integer number (9249160725511).

Almost surely, 2^{18498321451021} is an apocalyptic number.

It is an amenable number.

18498321451021 is a deficient number, since it is larger than the sum of its proper divisors (1).

18498321451021 is an equidigital number, since it uses as much as digits as its factorization.

18498321451021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 552960, while the sum is 49.

The spelling of 18498321451021 in words is "eighteen trillion, four hundred ninety-eight billion, three hundred twenty-one million, four hundred fifty-one thousand, twenty-one".