18475511557481 has 12 divisors (see below), whose sum is σ = 20610895102896. Its totient is φ = 16545234223320.

The previous prime is 18475511557463. The next prime is 18475511557507.

It is a happy number.

18475511557481 is nontrivially palindromic in base 10.

It is a de Polignac number, because none of the positive numbers 2^k-18475511557481 is a prime.

It is a super-2 number, since 2×18475511557481² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18475511551481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1139470835 + ... + 1139487048.

It is an arithmetic number, because the mean of its divisors is an integer number (1717574591908).

Almost surely, 2^{18475511557481} is an apocalyptic number.

18475511557481 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18475511557481 is a deficient number, since it is larger than the sum of its proper divisors (2135383545415).

18475511557481 is a wasteful number, since it uses less digits than its factorization.

18475511557481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2278957972 (or 2278957961 counting only the distinct ones).

The product of its digits is 31360000, while the sum is 62.

The spelling of 18475511557481 in words is "eighteen trillion, four hundred seventy-five billion, five hundred eleven million, five hundred fifty-seven thousand, four hundred eighty-one".