18215535481 has 16 divisors (see below), whose sum is σ = 21556297728. Its totient is φ = 15174172800.

The previous prime is 18215535463. The next prime is 18215535493. The reversal of 18215535481 is 18453551281.

It is a cyclic number.

It is not a de Polignac number, because 18215535481 - 2⁵ = 18215535449 is a prime.

It is a super-2 number, since 2×18215535481² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18215535431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 445305 + ... + 484486.

It is an arithmetic number, because the mean of its divisors is an integer number (1347268608).

Almost surely, 2^18215535481 is an apocalyptic number.

18215535481 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18215535481 is a deficient number, since it is larger than the sum of its proper divisors (3340762247).

18215535481 is a wasteful number, since it uses less digits than its factorization.

18215535481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 929952.

The product of its digits is 192000, while the sum is 43.

The spelling of 18215535481 in words is "eighteen billion, two hundred fifteen million, five hundred thirty-five thousand, four hundred eighty-one".