18075990781 has 4 divisors (see below), whose sum is σ = 18087240672. Its totient is φ = 18064740892.

The previous prime is 18075990763. The next prime is 18075990791. The reversal of 18075990781 is 18709957081.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18709957081 = 701 ⋅26690381.

It is a cyclic number.

It is not a de Polignac number, because 18075990781 - 2²⁹ = 17539119869 is a prime.

It is a super-2 number, since 2×18075990781² (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 (18075990791) 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, 5622535 + ... + 5625748.

It is an arithmetic number, because the mean of its divisors is an integer number (4521810168).

Almost surely, 2^18075990781 is an apocalyptic number.

It is an amenable number.

18075990781 is a deficient number, since it is larger than the sum of its proper divisors (11249891).

18075990781 is a wasteful number, since it uses less digits than its factorization.

18075990781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11249890.

The product of its (nonzero) digits is 1270080, while the sum is 55.

The spelling of 18075990781 in words is "eighteen billion, seventy-five million, nine hundred ninety thousand, seven hundred eighty-one".