21404042430 has 32 divisors (see below), whose sum is σ = 51394466304. Its totient is φ = 5704993056.

The previous prime is 21404042417. The next prime is 21404042437. The reversal of 21404042430 is 3424040412.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21404042430.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21404042437) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 108322 + ... + 233541.

It is an arithmetic number, because the mean of its divisors is an integer number (1606077072).

Almost surely, 2^21404042430 is an apocalyptic number.

21404042430 is an abundant number, since it is smaller than the sum of its proper divisors (29990423874).

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

21404042430 is a wasteful number, since it uses less digits than its factorization.

21404042430 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 343960.

The product of its (nonzero) digits is 3072, while the sum is 24.

Adding to 21404042430 its reverse (3424040412), we get a palindrome (24828082842).

The spelling of 21404042430 in words is "twenty-one billion, four hundred four million, forty-two thousand, four hundred thirty".