20243905 has 12 divisors (see below), whose sum is σ = 26702676. Its totient is φ = 14722400.

The previous prime is 20243891. The next prime is 20243939. The reversal of 20243905 is 50934202.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 8690704 + 11553201 = 2948^2 + 3399^2 .

It is not a de Polignac number, because 20243905 - 2⁷ = 20243777 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20243905.

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, 16126 + ... + 17335.

It is an arithmetic number, because the mean of its divisors is an integer number (2225223).

Almost surely, 2^20243905 is an apocalyptic number.

It is an amenable number.

20243905 is a deficient number, since it is larger than the sum of its proper divisors (6458771).

20243905 is a wasteful number, since it uses less digits than its factorization.

20243905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33488 (or 33477 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 20243905 is about 4499.3227268112. The cubic root of 20243905 is about 272.5407396375.

It can be divided in two parts, 2024 and 3905, that added together give a square (5929 = 77²).

The spelling of 20243905 in words is "twenty million, two hundred forty-three thousand, nine hundred five".