20426506 has 4 divisors (see below), whose sum is σ = 30639762. Its totient is φ = 10213252.

The previous prime is 20426473. The next prime is 20426509. The reversal of 20426506 is 60562402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 60562402 = 2 ⋅30281201.

It can be written as a sum of positive squares in only one way, i.e., 12355225 + 8071281 = 3515^2 + 2841^2 .

It is not an unprimeable number, because it can be changed into a prime (20426509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5106625 + ... + 5106628.

Almost surely, 2^20426506 is an apocalyptic number.

20426506 is a deficient number, since it is larger than the sum of its proper divisors (10213256).

20426506 is a wasteful number, since it uses less digits than its factorization.

20426506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10213255.

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 20426506 is about 4519.5692272605. The cubic root of 20426506 is about 273.3577316446.

Adding to 20426506 its reverse (60562402), we get a palindrome (80988908).

The spelling of 20426506 in words is "twenty million, four hundred twenty-six thousand, five hundred six".