18220494 has 16 divisors (see below), whose sum is σ = 36796032. Its totient is φ = 6014328.

The previous prime is 18220493. The next prime is 18220507. The reversal of 18220494 is 49402281.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18220493) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14124 + ... + 15359.

It is an arithmetic number, because the mean of its divisors is an integer number (2299752).

Almost surely, 2^18220494 is an apocalyptic number.

18220494 is an abundant number, since it is smaller than the sum of its proper divisors (18575538).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18220494 is a wasteful number, since it uses less digits than its factorization.

18220494 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29591.

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 18220494 is about 4268.5470595977. The cubic root of 18220494 is about 263.1399063816.

The spelling of 18220494 in words is "eighteen million, two hundred twenty thousand, four hundred ninety-four".