18491018537 has 2 divisors, whose sum is σ = 18491018538. Its totient is φ = 18491018536.

The previous prime is 18491018449. The next prime is 18491018543. The reversal of 18491018537 is 73581019481.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16999205161 + 1491813376 = 130381^2 + 38624^2 .

It is a cyclic number.

It is not a de Polignac number, because 18491018537 - 2⁸ = 18491018281 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18491018491 and 18491018500.

It is not a weakly prime, because it can be changed into another prime (18491018587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9245509268 + 9245509269.

It is an arithmetic number, because the mean of its divisors is an integer number (9245509269).

Almost surely, 2^18491018537 is an apocalyptic number.

It is an amenable number.

18491018537 is a deficient number, since it is larger than the sum of its proper divisors (1).

18491018537 is an equidigital number, since it uses as much as digits as its factorization.

18491018537 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 241920, while the sum is 47.

The spelling of 18491018537 in words is "eighteen billion, four hundred ninety-one million, eighteen thousand, five hundred thirty-seven".