18530949991 has 8 divisors (see below), whose sum is σ = 18621944480. Its totient is φ = 18440043552.

The previous prime is 18530949961. The next prime is 18530950001. The reversal of 18530949991 is 19994903581.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18530949991 - 2²⁵ = 18497395559 is a prime.

It is a super-2 number, since 2×18530949991² (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 (18530949961) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 421726 + ... + 463588.

It is an arithmetic number, because the mean of its divisors is an integer number (2327743060).

Almost surely, 2^18530949991 is an apocalyptic number.

18530949991 is a deficient number, since it is larger than the sum of its proper divisors (90994489).

18530949991 is a wasteful number, since it uses less digits than its factorization.

18530949991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44025.

The product of its (nonzero) digits is 3149280, while the sum is 58.

The spelling of 18530949991 in words is "eighteen billion, five hundred thirty million, nine hundred forty-nine thousand, nine hundred ninety-one".