21243550432 has 24 divisors (see below), whose sum is σ = 45040413096. Its totient is φ = 9804715392.

The previous prime is 21243550411. The next prime is 21243550459. The reversal of 21243550432 is 23405534212.

It is a junction number, because it is equal to n+sod(n) for n = 21243550394 and 21243550403.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25532698 + ... + 25533529.

It is an arithmetic number, because the mean of its divisors is an integer number (1876683879).

Almost surely, 2^21243550432 is an apocalyptic number.

It is an amenable number.

21243550432 is an abundant number, since it is smaller than the sum of its proper divisors (23796862664).

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

21243550432 is a wasteful number, since it uses less digits than its factorization.

21243550432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51066250 (or 51066242 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 31.

The spelling of 21243550432 in words is "twenty-one billion, two hundred forty-three million, five hundred fifty thousand, four hundred thirty-two".