21220020231 has 8 divisors (see below), whose sum is σ = 28295339904. Its totient is φ = 14145690360.

The previous prime is 21220020223. The next prime is 21220020233. The reversal of 21220020231 is 13202002212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21220020231 - 2³ = 21220020223 is a prime.

It is a super-2 number, since 2×21220020231² (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 21220020231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220020233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 195891 + ... + 284276.

It is an arithmetic number, because the mean of its divisors is an integer number (3536917488).

Almost surely, 2^21220020231 is an apocalyptic number.

21220020231 is a deficient number, since it is larger than the sum of its proper divisors (7075319673).

21220020231 is a wasteful number, since it uses less digits than its factorization.

21220020231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 494901.

The product of its (nonzero) digits is 96, while the sum is 15.

Adding to 21220020231 its reverse (13202002212), we get a palindrome (34422022443).

The spelling of 21220020231 in words is "twenty-one billion, two hundred twenty million, twenty thousand, two hundred thirty-one".