20686426 has 4 divisors (see below), whose sum is σ = 31029642. Its totient is φ = 10343212.

The previous prime is 20686411. The next prime is 20686429. The reversal of 20686426 is 62468602.

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., 13315201 + 7371225 = 3649^2 + 2715^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20686391 and 20686400.

It is not an unprimeable number, because it can be changed into a prime (20686429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5171605 + ... + 5171608.

Almost surely, 2^20686426 is an apocalyptic number.

20686426 is a deficient number, since it is larger than the sum of its proper divisors (10343216).

20686426 is a wasteful number, since it uses less digits than its factorization.

20686426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10343215.

The product of its (nonzero) digits is 27648, while the sum is 34.

The square root of 20686426 is about 4548.2332833750. The cubic root of 20686426 is about 274.5123080779.

It can be divided in two parts, 20686 and 426, that added together give a palindrome (21112).

The spelling of 20686426 in words is "twenty million, six hundred eighty-six thousand, four hundred twenty-six".