18355201481 has 4 divisors (see below), whose sum is σ = 18802889364. Its totient is φ = 17907513600.

The previous prime is 18355201471. The next prime is 18355201489. The reversal of 18355201481 is 18410255381.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6787123456 + 11568078025 = 82384^2 + 107555^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18355201481 is a prime.

It is a super-2 number, since 2×18355201481² (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 (18355201489) 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, 223843880 + ... + 223843961.

It is an arithmetic number, because the mean of its divisors is an integer number (4700722341).

Almost surely, 2^18355201481 is an apocalyptic number.

It is an amenable number.

18355201481 is a deficient number, since it is larger than the sum of its proper divisors (447687883).

18355201481 is an equidigital number, since it uses as much as digits as its factorization.

18355201481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 447687882.

The product of its (nonzero) digits is 38400, while the sum is 38.

The spelling of 18355201481 in words is "eighteen billion, three hundred fifty-five million, two hundred one thousand, four hundred eighty-one".