18153215557 has 4 divisors (see below), whose sum is σ = 18154572460. Its totient is φ = 18151858656.

The previous prime is 18153215527. The next prime is 18153215599. The reversal of 18153215557 is 75551235181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75551235181 = 19 ⋅3976380799.

It can be written as a sum of positive squares in 2 ways, for example, as 5869704996 + 12283510561 = 76614^2 + 110831^2 .

It is a cyclic number.

It is not a de Polignac number, because 18153215557 - 2¹¹ = 18153213509 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 (18153215527) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 658182 + ... + 685207.

It is an arithmetic number, because the mean of its divisors is an integer number (4538643115).

Almost surely, 2^18153215557 is an apocalyptic number.

It is an amenable number.

18153215557 is a deficient number, since it is larger than the sum of its proper divisors (1356903).

18153215557 is a wasteful number, since it uses less digits than its factorization.

18153215557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1356902.

The product of its digits is 210000, while the sum is 43.

The spelling of 18153215557 in words is "eighteen billion, one hundred fifty-three million, two hundred fifteen thousand, five hundred fifty-seven".