18275859781 has 4 divisors (see below), whose sum is σ = 18376831564. Its totient is φ = 18174888000.

The previous prime is 18275859751. The next prime is 18275859841. The reversal of 18275859781 is 18795857281.

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 938870881 + 17336988900 = 30641^2 + 131670^2 .

It is a cyclic number.

It is not a de Polignac number, because 18275859781 - 2¹⁵ = 18275827013 is a prime.

It is a super-2 number, since 2×18275859781² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18275859751) 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, 50485620 + ... + 50485981.

It is an arithmetic number, because the mean of its divisors is an integer number (4594207891).

Almost surely, 2^18275859781 is an apocalyptic number.

It is an amenable number.

18275859781 is a deficient number, since it is larger than the sum of its proper divisors (100971783).

18275859781 is a wasteful number, since it uses less digits than its factorization.

18275859781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100971782.

The product of its digits is 11289600, while the sum is 61.

The spelling of 18275859781 in words is "eighteen billion, two hundred seventy-five million, eight hundred fifty-nine thousand, seven hundred eighty-one".