18995216909 has 8 divisors (see below), whose sum is σ = 19123004472. Its totient is φ = 18867732480.

The previous prime is 18995216881. The next prime is 18995216941. The reversal of 18995216909 is 90961259981.

It can be written as a sum of positive squares in 4 ways, for example, as 446138884 + 18549078025 = 21122^2 + 136195^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18995216909 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 (18995216969) 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, 50669 + ... + 201389.

It is an arithmetic number, because the mean of its divisors is an integer number (2390375559).

Almost surely, 2^18995216909 is an apocalyptic number.

It is an amenable number.

18995216909 is a deficient number, since it is larger than the sum of its proper divisors (127787563).

18995216909 is a wasteful number, since it uses less digits than its factorization.

18995216909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151567.

The product of its (nonzero) digits is 3149280, while the sum is 59.

The spelling of 18995216909 in words is "eighteen billion, nine hundred ninety-five million, two hundred sixteen thousand, nine hundred nine".