18021765007 has 4 divisors (see below), whose sum is σ = 18142716600. Its totient is φ = 17900813416.

The previous prime is 18021764951. The next prime is 18021765037. The reversal of 18021765007 is 70056712081.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18021765007 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18021765037) 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, 60475573 + ... + 60475870.

It is an arithmetic number, because the mean of its divisors is an integer number (4535679150).

Almost surely, 2^18021765007 is an apocalyptic number.

18021765007 is a deficient number, since it is larger than the sum of its proper divisors (120951593).

18021765007 is a wasteful number, since it uses less digits than its factorization.

18021765007 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120951592.

The product of its (nonzero) digits is 23520, while the sum is 37.

The spelling of 18021765007 in words is "eighteen billion, twenty-one million, seven hundred sixty-five thousand, seven".