20405427 has 16 divisors (see below), whose sum is σ = 31372800. Its totient is φ = 11555712.

The previous prime is 20405387. The next prime is 20405443. The reversal of 20405427 is 72450402.

It is not a de Polignac number, because 20405427 - 2¹¹ = 20403379 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20405397 and 20405406.

It is not an unprimeable number, because it can be changed into a prime (20405027) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1927 + ... + 6672.

It is an arithmetic number, because the mean of its divisors is an integer number (1960800).

Almost surely, 2^20405427 is an apocalyptic number.

20405427 is a deficient number, since it is larger than the sum of its proper divisors (10967373).

20405427 is a wasteful number, since it uses less digits than its factorization.

20405427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8722.

The product of its (nonzero) digits is 2240, while the sum is 24.

The square root of 20405427 is about 4517.2366553016. The cubic root of 20405427 is about 273.2636693704.

Adding to 20405427 its reverse (72450402), we get a palindrome (92855829).

The spelling of 20405427 in words is "twenty million, four hundred five thousand, four hundred twenty-seven".