20938405 has 8 divisors (see below), whose sum is σ = 25150752. Its totient is φ = 16734288.

The previous prime is 20938403. The next prime is 20938417. The reversal of 20938405 is 50483902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20938405 - 2¹ = 20938403 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20938403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8214 + ... + 10456.

It is an arithmetic number, because the mean of its divisors is an integer number (3143844).

Almost surely, 2^20938405 is an apocalyptic number.

It is an amenable number.

20938405 is a deficient number, since it is larger than the sum of its proper divisors (4212347).

20938405 is a wasteful number, since it uses less digits than its factorization.

20938405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4115.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 20938405 is about 4575.8501942262. The cubic root of 20938405 is about 275.6224139048.

The spelling of 20938405 in words is "twenty million, nine hundred thirty-eight thousand, four hundred five".