20631826 has 4 divisors (see below), whose sum is σ = 30947742. Its totient is φ = 10315912.

The previous prime is 20631823. The next prime is 20631857. The reversal of 20631826 is 62813602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 62813602 = 2 ⋅31406801.

It can be written as a sum of positive squares in only one way, i.e., 11323225 + 9308601 = 3365^2 + 3051^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20631794 and 20631803.

It is not an unprimeable number, because it can be changed into a prime (20631823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5157955 + ... + 5157958.

Almost surely, 2^20631826 is an apocalyptic number.

20631826 is a deficient number, since it is larger than the sum of its proper divisors (10315916).

20631826 is a wasteful number, since it uses less digits than its factorization.

20631826 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10315915.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 20631826 is about 4542.2269868425. The cubic root of 20631826 is about 274.2705782560.

The spelling of 20631826 in words is "twenty million, six hundred thirty-one thousand, eight hundred twenty-six".