18420497 has 4 divisors (see below), whose sum is σ = 18464880. Its totient is φ = 18376116.

The previous prime is 18420491. The next prime is 18420517. The reversal of 18420497 is 79402481.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18420497 - 2⁶ = 18420433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18420491) 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, 21563 + ... + 22400.

It is an arithmetic number, because the mean of its divisors is an integer number (4616220).

Almost surely, 2^18420497 is an apocalyptic number.

It is an amenable number.

18420497 is a deficient number, since it is larger than the sum of its proper divisors (44383).

18420497 is an equidigital number, since it uses as much as digits as its factorization.

18420497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44382.

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 18420497 is about 4291.9106467866. The cubic root of 18420497 is about 264.0992175662.

The spelling of 18420497 in words is "eighteen million, four hundred twenty thousand, four hundred ninety-seven".