21220002423 has 72 divisors (see below), whose sum is σ = 33236356608. Its totient is φ = 13020118848.

The previous prime is 21220002421. The next prime is 21220002431. The reversal of 21220002423 is 32420002212.

21220002423 is a `hidden beast` number, since 21 + 220 + 0 + 0 + 2 + 423 = 666.

It is not a de Polignac number, because 21220002423 - 2¹ = 21220002421 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21220002396 and 21220002405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220002421) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 29188086 + ... + 29188812.

It is an arithmetic number, because the mean of its divisors is an integer number (461616064).

Almost surely, 2^21220002423 is an apocalyptic number.

21220002423 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21220002423 is a deficient number, since it is larger than the sum of its proper divisors (12016354185).

21220002423 is a wasteful number, since it uses less digits than its factorization.

21220002423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 933 (or 893 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

Adding to 21220002423 its reverse (32420002212), we get a palindrome (53640004635).

The spelling of 21220002423 in words is "twenty-one billion, two hundred twenty million, two thousand, four hundred twenty-three".