21432232440 has 48 divisors (see below), whose sum is σ = 69654756600. Its totient is φ = 5715261888.

The previous prime is 21432232433. The next prime is 21432232477. The reversal of 21432232440 is 4423223412.

21432232440 is a `hidden beast` number, since 2 + 14 + 322 + 324 + 4 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 29766630 + ... + 29767349.

Almost surely, 2^21432232440 is an apocalyptic number.

21432232440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21432232440 is an abundant number, since it is smaller than the sum of its proper divisors (48222524160).

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

21432232440 is a wasteful number, since it uses less digits than its factorization.

21432232440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59533996 (or 59533989 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 27.

Adding to 21432232440 its reverse (4423223412), we get a palindrome (25855455852).

The spelling of 21432232440 in words is "twenty-one billion, four hundred thirty-two million, two hundred thirty-two thousand, four hundred forty".