18438823451 has 4 divisors (see below), whose sum is σ = 18439592304. Its totient is φ = 18438054600.

The previous prime is 18438823369. The next prime is 18438823519. The reversal of 18438823451 is 15432883481.

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-18438823451 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18438823396 and 18438823405.

It is not an unprimeable number, because it can be changed into a prime (18438823651) 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, 347255 + ... + 396816.

It is an arithmetic number, because the mean of its divisors is an integer number (4609898076).

Almost surely, 2^18438823451 is an apocalyptic number.

18438823451 is a deficient number, since it is larger than the sum of its proper divisors (768853).

18438823451 is an equidigital number, since it uses as much as digits as its factorization.

18438823451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 768852.

The product of its digits is 737280, while the sum is 47.

The spelling of 18438823451 in words is "eighteen billion, four hundred thirty-eight million, eight hundred twenty-three thousand, four hundred fifty-one".