18440686406 has 8 divisors (see below), whose sum is σ = 27663537960. Its totient is φ = 9219507088.

The previous prime is 18440686391. The next prime is 18440686409. The reversal of 18440686406 is 60468604481.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18440686409) 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, 390116 + ... + 434823.

It is an arithmetic number, because the mean of its divisors is an integer number (3457942245).

Almost surely, 2^18440686406 is an apocalyptic number.

18440686406 is a deficient number, since it is larger than the sum of its proper divisors (9222851554).

18440686406 is a wasteful number, since it uses less digits than its factorization.

18440686406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 836118.

The product of its (nonzero) digits is 884736, while the sum is 47.

The spelling of 18440686406 in words is "eighteen billion, four hundred forty million, six hundred eighty-six thousand, four hundred six".