18791421363 has 256 divisors, whose sum is σ = 36400896000. Its totient is φ = 9484231680.

The previous prime is 18791421343. The next prime is 18791421371. The reversal of 18791421363 is 36312419781.

18791421363 is a `hidden beast` number, since 1 + 87 + 91 + 421 + 3 + 63 = 666.

It is not a de Polignac number, because 18791421363 - 2¹⁶ = 18791355827 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18791421323) by changing a digit.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 257416695 + ... + 257416767.

It is an arithmetic number, because the mean of its divisors is an integer number (142191000).

Almost surely, 2^18791421363 is an apocalyptic number.

18791421363 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

18791421363 is a deficient number, since it is larger than the sum of its proper divisors (17609474637).

18791421363 is a wasteful number, since it uses less digits than its factorization.

18791421363 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176 (or 148 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The spelling of 18791421363 in words is "eighteen billion, seven hundred ninety-one million, four hundred twenty-one thousand, three hundred sixty-three".