20939393 has 16 divisors (see below), whose sum is σ = 23016960. Its totient is φ = 18971136.

The previous prime is 20939389. The next prime is 20939419. The reversal of 20939393 is 39393902.

It is a cyclic number.

It is not a de Polignac number, because 20939393 - 2² = 20939389 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20939333) 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 15 ways as a sum of consecutive naturals, for example, 58148 + ... + 58506.

It is an arithmetic number, because the mean of its divisors is an integer number (1438560).

Almost surely, 2^20939393 is an apocalyptic number.

It is an amenable number.

20939393 is a deficient number, since it is larger than the sum of its proper divisors (2077567).

20939393 is a wasteful number, since it uses less digits than its factorization.

20939393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 496.

The product of its (nonzero) digits is 39366, while the sum is 38.

The square root of 20939393 is about 4575.9581510324. The cubic root of 20939393 is about 275.6267490115.

The spelling of 20939393 in words is "twenty million, nine hundred thirty-nine thousand, three hundred ninety-three".