18735721337 has 2 divisors, whose sum is σ = 18735721338. Its totient is φ = 18735721336.

The previous prime is 18735721289. The next prime is 18735721351. The reversal of 18735721337 is 73312753781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16686438976 + 2049282361 = 129176^2 + 45269^2 .

It is an emirp because it is prime and its reverse (73312753781) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18735721337 - 2¹² = 18735717241 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18735721291 and 18735721300.

It is not a weakly prime, because it can be changed into another prime (18735721387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9367860668 + 9367860669.

It is an arithmetic number, because the mean of its divisors is an integer number (9367860669).

Almost surely, 2^18735721337 is an apocalyptic number.

It is an amenable number.

18735721337 is a deficient number, since it is larger than the sum of its proper divisors (1).

18735721337 is an equidigital number, since it uses as much as digits as its factorization.

18735721337 is an evil number, because the sum of its binary digits is even.

The product of its digits is 740880, while the sum is 47.

The spelling of 18735721337 in words is "eighteen billion, seven hundred thirty-five million, seven hundred twenty-one thousand, three hundred thirty-seven".