21403244420 has 12 divisors (see below), whose sum is σ = 44946813324. Its totient is φ = 8561297760.

The previous prime is 21403244381. The next prime is 21403244461. The reversal of 21403244420 is 2444230412.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 6937890436 + 14465353984 = 83294^2 + 120272^2 .

It is a super-2 number, since 2×21403244420² (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 21403244420.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 535081091 + ... + 535081130.

It is an arithmetic number, because the mean of its divisors is an integer number (3745567777).

Almost surely, 2^21403244420 is an apocalyptic number.

21403244420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21403244420 is an abundant number, since it is smaller than the sum of its proper divisors (23543568904).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21403244420 is a wasteful number, since it uses less digits than its factorization.

21403244420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1070162230 (or 1070162228 counting only the distinct ones).

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

Adding to 21403244420 its reverse (2444230412), we get a palindrome (23847474832).

The spelling of 21403244420 in words is "twenty-one billion, four hundred three million, two hundred forty-four thousand, four hundred twenty".