20420444231 has 4 divisors (see below), whose sum is σ = 22276848264. Its totient is φ = 18564040200.

The previous prime is 20420444197. The next prime is 20420444287. The reversal of 20420444231 is 13244402402.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 20420444231 - 2¹⁰ = 20420443207 is a prime.

It is a super-2 number, since 2×20420444231² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20420444231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20420444831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 928202000 + ... + 928202021.

It is an arithmetic number, because the mean of its divisors is an integer number (5569212066).

Almost surely, 2^20420444231 is an apocalyptic number.

20420444231 is a deficient number, since it is larger than the sum of its proper divisors (1856404033).

20420444231 is a wasteful number, since it uses less digits than its factorization.

20420444231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1856404032.

The product of its (nonzero) digits is 6144, while the sum is 26.

Adding to 20420444231 its reverse (13244402402), we get a palindrome (33664846633).

The spelling of 20420444231 in words is "twenty billion, four hundred twenty million, four hundred forty-four thousand, two hundred thirty-one".