21420242430 has 32 divisors (see below), whose sum is σ = 52027968384. Its totient is φ = 5643243936.

The previous prime is 21420242407. The next prime is 21420242449. The reversal of 21420242430 is 3424202412.

It is a self number, because there is not a number n which added to its sum of digits gives 21420242430.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4298764 + ... + 4303743.

It is an arithmetic number, because the mean of its divisors is an integer number (1625874012).

Almost surely, 2^21420242430 is an apocalyptic number.

21420242430 is an abundant number, since it is smaller than the sum of its proper divisors (30607725954).

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

21420242430 is a wasteful number, since it uses less digits than its factorization.

21420242430 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8602600.

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

Adding to 21420242430 its reverse (3424202412), we get a palindrome (24844444842).

The spelling of 21420242430 in words is "twenty-one billion, four hundred twenty million, two hundred forty-two thousand, four hundred thirty".