21523031430 has 32 divisors (see below), whose sum is σ = 51748053984. Its totient is φ = 5729166336.

The previous prime is 21523031423. The next prime is 21523031443. The reversal of 21523031430 is 3413032512.

It is a self number, because there is not a number n which added to its sum of digits gives 21523031430.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 627307 + ... + 660726.

It is an arithmetic number, because the mean of its divisors is an integer number (1617126687).

Almost surely, 2^21523031430 is an apocalyptic number.

21523031430 is an abundant number, since it is smaller than the sum of its proper divisors (30225022554).

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

21523031430 is a wasteful number, since it uses less digits than its factorization.

21523031430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1288600.

The product of its (nonzero) digits is 2160, while the sum is 24.

Adding to 21523031430 its reverse (3413032512), we get a palindrome (24936063942).

The spelling of 21523031430 in words is "twenty-one billion, five hundred twenty-three million, thirty-one thousand, four hundred thirty".