18420779 has 8 divisors (see below), whose sum is σ = 20134800. Its totient is φ = 16749216.

The previous prime is 18420763. The next prime is 18420791. The reversal of 18420779 is 97702481.

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 18420779 - 2⁴ = 18420763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18420739) 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, 9704 + ... + 11445.

It is an arithmetic number, because the mean of its divisors is an integer number (2516850).

Almost surely, 2^18420779 is an apocalyptic number.

18420779 is a deficient number, since it is larger than the sum of its proper divisors (1714021).

18420779 is a wasteful number, since it uses less digits than its factorization.

18420779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21229.

The product of its (nonzero) digits is 28224, while the sum is 38.

The square root of 18420779 is about 4291.9434991621. The cubic root of 18420779 is about 264.1005652605.

The spelling of 18420779 in words is "eighteen million, four hundred twenty thousand, seven hundred seventy-nine".