21012365430 has 192 divisors, whose sum is σ = 65824012800. Its totient is φ = 4543050240.

The previous prime is 21012365417. The next prime is 21012365441. The reversal of 21012365430 is 3456321012.

21012365430 is a `hidden beast` number, since 2 + 1 + 0 + 1 + 2 + 3 + 654 + 3 + 0 = 666.

It is an alternating number because its digits alternate between even and odd.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21012365394 and 21012365403.

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 95 ways as a sum of consecutive naturals, for example, 13058466 + ... + 13060074.

It is an arithmetic number, because the mean of its divisors is an integer number (342833400).

Almost surely, 2^21012365430 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21012365430, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32912006400).

21012365430 is an abundant number, since it is smaller than the sum of its proper divisors (44811647370).

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

21012365430 is a wasteful number, since it uses less digits than its factorization.

21012365430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2739 (or 2736 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

Adding to 21012365430 its reverse (3456321012), we get a palindrome (24468686442).

The spelling of 21012365430 in words is "twenty-one billion, twelve million, three hundred sixty-five thousand, four hundred thirty".