20506426 has 4 divisors (see below), whose sum is σ = 30759642. Its totient is φ = 10253212.

The previous prime is 20506417. The next prime is 20506427. The reversal of 20506426 is 62460502.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 20205025 + 301401 = 4495^2 + 549^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20506426.

It is not an unprimeable number, because it can be changed into a prime (20506427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5126605 + ... + 5126608.

Almost surely, 2^20506426 is an apocalyptic number.

20506426 is a deficient number, since it is larger than the sum of its proper divisors (10253216).

20506426 is a wasteful number, since it uses less digits than its factorization.

20506426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10253215.

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

The square root of 20506426 is about 4528.4021464530. The cubic root of 20506426 is about 273.7137775165.

Adding to 20506426 its reverse (62460502), we get a palindrome (82966928).

The spelling of 20506426 in words is "twenty million, five hundred six thousand, four hundred twenty-six".