21424220432 has 20 divisors (see below), whose sum is σ = 41517224796. Its totient is φ = 10710097920.

The previous prime is 21424220407. The next prime is 21424220443. The reversal of 21424220432 is 23402242412.

It can be written as a sum of positive squares in 2 ways, for example, as 19640340736 + 1783879696 = 140144^2 + 42236^2 .

It is a super-2 number, since 2×21424220432² (a number of 21 digits) contains 22 as substring.

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 3 ways as a sum of consecutive naturals, for example, 35993 + ... + 210104.

Almost surely, 2^21424220432 is an apocalyptic number.

It is an amenable number.

21424220432 is a deficient number, since it is larger than the sum of its proper divisors (20093004364).

21424220432 is a wasteful number, since it uses less digits than its factorization.

21424220432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 251546 (or 251540 counting only the distinct ones).

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

Adding to 21424220432 its reverse (23402242412), we get a palindrome (44826462844).

The spelling of 21424220432 in words is "twenty-one billion, four hundred twenty-four million, two hundred twenty thousand, four hundred thirty-two".