20391244 has 6 divisors (see below), whose sum is σ = 35684684. Its totient is φ = 10195620.

The previous prime is 20391229. The next prime is 20391257. The reversal of 20391244 is 44219302.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2548902 + ... + 2548909.

Almost surely, 2^20391244 is an apocalyptic number.

It is an amenable number.

20391244 is a deficient number, since it is larger than the sum of its proper divisors (15293440).

20391244 is a wasteful number, since it uses less digits than its factorization.

20391244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5097815 (or 5097813 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 20391244 is about 4515.6665067297. Note that the first 3 decimals coincide. The cubic root of 20391244 is about 273.2003431302.

The spelling of 20391244 in words is "twenty million, three hundred ninety-one thousand, two hundred forty-four".