21820422309 has 24 divisors (see below), whose sum is σ = 33853917888. Its totient is φ = 12465129600.

The previous prime is 21820422287. The next prime is 21820422311. The reversal of 21820422309 is 90322402812.

It is not a de Polignac number, because 21820422309 - 2⁵ = 21820422277 is a prime.

It is a super-2 number, since 2×21820422309² (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 21820422309.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21820422329) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 523384 + ... + 563534.

It is an arithmetic number, because the mean of its divisors is an integer number (1410579912).

Almost surely, 2^21820422309 is an apocalyptic number.

It is an amenable number.

21820422309 is a deficient number, since it is larger than the sum of its proper divisors (12033495579).

21820422309 is a wasteful number, since it uses less digits than its factorization.

21820422309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43865 (or 43858 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 33.

The spelling of 21820422309 in words is "twenty-one billion, eight hundred twenty million, four hundred twenty-two thousand, three hundred nine".