21205300430 has 16 divisors (see below), whose sum is σ = 38197487520. Its totient is φ = 8475909792.

The previous prime is 21205300429. The next prime is 21205300433. The reversal of 21205300430 is 3400350212.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21205300433) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 761945 + ... + 789284.

It is an arithmetic number, because the mean of its divisors is an integer number (2387342970).

Almost surely, 2^21205300430 is an apocalyptic number.

21205300430 is a deficient number, since it is larger than the sum of its proper divisors (16992187090).

21205300430 is a wasteful number, since it uses less digits than its factorization.

21205300430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1552603.

The product of its (nonzero) digits is 720, while the sum is 20.

Adding to 21205300430 its reverse (3400350212), we get a palindrome (24605650642).

The spelling of 21205300430 in words is "twenty-one billion, two hundred five million, three hundred thousand, four hundred thirty".