18243564815 has 16 divisors (see below), whose sum is σ = 25040162880. Its totient is φ = 12499664640.

The previous prime is 18243564811. The next prime is 18243564839. The reversal of 18243564815 is 51846534281.

It is not a de Polignac number, because 18243564815 - 2² = 18243564811 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18243564815.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18243564811) 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, 169046 + ... + 255075.

It is an arithmetic number, because the mean of its divisors is an integer number (1565010180).

Almost surely, 2^18243564815 is an apocalyptic number.

18243564815 is a deficient number, since it is larger than the sum of its proper divisors (6796598065).

18243564815 is a wasteful number, since it uses less digits than its factorization.

18243564815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425362.

The product of its digits is 921600, while the sum is 47.

The spelling of 18243564815 in words is "eighteen billion, two hundred forty-three million, five hundred sixty-four thousand, eight hundred fifteen".