18449643 has 16 divisors (see below), whose sum is σ = 25390080. Its totient is φ = 11907936.

The previous prime is 18449603. The next prime is 18449663. The reversal of 18449643 is 34694481.

It is a happy number.

It is not a de Polignac number, because 18449643 - 2⁶ = 18449579 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18449603) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38278 + ... + 38756.

It is an arithmetic number, because the mean of its divisors is an integer number (1586880).

Almost surely, 2^18449643 is an apocalyptic number.

18449643 is a deficient number, since it is larger than the sum of its proper divisors (6940437).

18449643 is a wasteful number, since it uses less digits than its factorization.

18449643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 866.

The product of its digits is 82944, while the sum is 39.

The square root of 18449643 is about 4295.3047621793. The cubic root of 18449643 is about 264.2384353006.

The spelling of 18449643 in words is "eighteen million, four hundred forty-nine thousand, six hundred forty-three".