18685537001 has 2 divisors, whose sum is σ = 18685537002. Its totient is φ = 18685537000.

The previous prime is 18685536983. The next prime is 18685537021. The reversal of 18685537001 is 10073558681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18057984400 + 627552601 = 134380^2 + 25051^2 .

It is a cyclic number.

It is not a de Polignac number, because 18685537001 - 2¹⁸ = 18685274857 is a prime.

It is not a weakly prime, because it can be changed into another prime (18685537021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9342768500 + 9342768501.

It is an arithmetic number, because the mean of its divisors is an integer number (9342768501).

Almost surely, 2^18685537001 is an apocalyptic number.

It is an amenable number.

18685537001 is a deficient number, since it is larger than the sum of its proper divisors (1).

18685537001 is an equidigital number, since it uses as much as digits as its factorization.

18685537001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 201600, while the sum is 44.

The spelling of 18685537001 in words is "eighteen billion, six hundred eighty-five million, five hundred thirty-seven thousand, one".