20826431 has 4 divisors (see below), whose sum is σ = 21731952. Its totient is φ = 19920912.

The previous prime is 20826427. The next prime is 20826439. The reversal of 20826431 is 13462802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13462802 = 2 ⋅6731401.

It is a cyclic number.

It is not a de Polignac number, because 20826431 - 2² = 20826427 is a prime.

It is a super-2 number, since 2×20826431² = 867480456395522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20826431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20826439) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 452726 + ... + 452771.

It is an arithmetic number, because the mean of its divisors is an integer number (5432988).

Almost surely, 2^20826431 is an apocalyptic number.

20826431 is a deficient number, since it is larger than the sum of its proper divisors (905521).

20826431 is an equidigital number, since it uses as much as digits as its factorization.

20826431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 905520.

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 20826431 is about 4563.5984705055. The cubic root of 20826431 is about 275.1302127146.

The spelling of 20826431 in words is "twenty million, eight hundred twenty-six thousand, four hundred thirty-one".