18505519912909 has 16 divisors (see below), whose sum is σ = 19612887384960. Its totient is φ = 17400245747200.

The previous prime is 18505519912907. The next prime is 18505519912927. The reversal of 18505519912909 is 90921991550581.

It is a cyclic number.

It is not a de Polignac number, because 18505519912909 - 2¹ = 18505519912907 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18505519912907) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 181484262 + ... + 181586200.

It is an arithmetic number, because the mean of its divisors is an integer number (1225805461560).

Almost surely, 2^{18505519912909} is an apocalyptic number.

It is an amenable number.

18505519912909 is a deficient number, since it is larger than the sum of its proper divisors (1107367472051).

18505519912909 is a wasteful number, since it uses less digits than its factorization.

18505519912909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112100.

The product of its (nonzero) digits is 13122000, while the sum is 64.

The spelling of 18505519912909 in words is "eighteen trillion, five hundred five billion, five hundred nineteen million, nine hundred twelve thousand, nine hundred nine".