21423410440 has 16 divisors (see below), whose sum is σ = 48202673580. Its totient is φ = 8569364160.

The previous prime is 21423410431. The next prime is 21423410447. The reversal of 21423410440 is 4401432412.

It can be written as a sum of positive squares in 2 ways, for example, as 21304905444 + 118504996 = 145962^2 + 10886^2 .

It is not an unprimeable number, because it can be changed into a prime (21423410447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 267792591 + ... + 267792670.

Almost surely, 2^21423410440 is an apocalyptic number.

21423410440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21423410440 is an abundant number, since it is smaller than the sum of its proper divisors (26779263140).

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

21423410440 is a wasteful number, since it uses less digits than its factorization.

21423410440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 535585272 (or 535585268 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 25.

Adding to 21423410440 its reverse (4401432412), we get a palindrome (25824842852).

The spelling of 21423410440 in words is "twenty-one billion, four hundred twenty-three million, four hundred ten thousand, four hundred forty".