21433043440 has 20 divisors (see below), whose sum is σ = 49831826184. Its totient is φ = 8573217344.

The previous prime is 21433043431. The next prime is 21433043441. The reversal of 21433043440 is 4434033412.

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×21433043440² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21433043399 and 21433043408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21433043441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 133956442 + ... + 133956601.

Almost surely, 2^21433043440 is an apocalyptic number.

21433043440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21433043440 is an abundant number, since it is smaller than the sum of its proper divisors (28398782744).

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

21433043440 is a wasteful number, since it uses less digits than its factorization.

21433043440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 267913056 (or 267913050 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 28.

Adding to 21433043440 its reverse (4434033412), we get a palindrome (25867076852).

The spelling of 21433043440 in words is "twenty-one billion, four hundred thirty-three million, forty-three thousand, four hundred forty".