18936363721 has 8 divisors (see below), whose sum is σ = 20808640224. Its totient is φ = 17089218720.

The previous prime is 18936363709. The next prime is 18936363727. The reversal of 18936363721 is 12736363981.

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 18936363721 - 2¹¹ = 18936361673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18936363727) 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, 6281295 + ... + 6284308.

It is an arithmetic number, because the mean of its divisors is an integer number (2601080028).

Almost surely, 2^18936363721 is an apocalyptic number.

18936363721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18936363721 is a deficient number, since it is larger than the sum of its proper divisors (1872276503).

18936363721 is a wasteful number, since it uses less digits than its factorization.

18936363721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12565751.

The product of its digits is 979776, while the sum is 49.

The spelling of 18936363721 in words is "eighteen billion, nine hundred thirty-six million, three hundred sixty-three thousand, seven hundred twenty-one".