21432031440 has 40 divisors (see below), whose sum is σ = 66439298208. Its totient is φ = 5715208320.

The previous prime is 21432031417. The next prime is 21432031451. The reversal of 21432031440 is 4413023412.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 21432031440.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 44649826 + ... + 44650305.

Almost surely, 2^21432031440 is an apocalyptic number.

21432031440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21432031440 is an abundant number, since it is smaller than the sum of its proper divisors (45007266768).

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

21432031440 is a wasteful number, since it uses less digits than its factorization.

21432031440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89300147 (or 89300141 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 24.

Adding to 21432031440 its reverse (4413023412), we get a palindrome (25845054852).

The spelling of 21432031440 in words is "twenty-one billion, four hundred thirty-two million, thirty-one thousand, four hundred forty".