20903405 has 12 divisors (see below), whose sum is σ = 25537692. Its totient is φ = 16425600.

The previous prime is 20903371. The next prime is 20903411. The reversal of 20903405 is 50430902.

It can be written as a sum of positive squares in 2 ways, for example, as 2353156 + 18550249 = 1534^2 + 4307^2 .

It is not a de Polignac number, because 20903405 - 2¹⁰ = 20902381 is a prime.

It is a hoax number, since the sum of its digits (23) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16805 + ... + 18005.

It is an arithmetic number, because the mean of its divisors is an integer number (2128141).

Almost surely, 2^20903405 is an apocalyptic number.

It is an amenable number.

20903405 is a deficient number, since it is larger than the sum of its proper divisors (4634287).

20903405 is an equidigital number, since it uses as much as digits as its factorization.

20903405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1324 (or 1265 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 20903405 is about 4572.0241687900. The cubic root of 20903405 is about 275.4687542449.

The spelling of 20903405 in words is "twenty million, nine hundred three thousand, four hundred five".