20994439 has 4 divisors (see below), whose sum is σ = 22229424. Its totient is φ = 19759456.

The previous prime is 20994437. The next prime is 20994443. The reversal of 20994439 is 93449902.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20994439 - 2¹ = 20994437 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20994433) 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, 617467 + ... + 617500.

It is an arithmetic number, because the mean of its divisors is an integer number (5557356).

Almost surely, 2^20994439 is an apocalyptic number.

20994439 is a deficient number, since it is larger than the sum of its proper divisors (1234985).

20994439 is a wasteful number, since it uses less digits than its factorization.

20994439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1234984.

The product of its (nonzero) digits is 69984, while the sum is 40.

The square root of 20994439 is about 4581.9688999381. The cubic root of 20994439 is about 275.8680625082.

The spelling of 20994439 in words is "twenty million, nine hundred ninety-four thousand, four hundred thirty-nine".