21430420421 has 8 divisors (see below), whose sum is σ = 22158287424. Its totient is φ = 20712323680.

The previous prime is 21430420399. The next prime is 21430420423. The reversal of 21430420421 is 12402403412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21430420421 - 2²² = 21426226117 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21430420423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2438105 + ... + 2446878.

It is an arithmetic number, because the mean of its divisors is an integer number (2769785928).

Almost surely, 2^21430420421 is an apocalyptic number.

It is an amenable number.

21430420421 is a deficient number, since it is larger than the sum of its proper divisors (727867003).

21430420421 is a wasteful number, since it uses less digits than its factorization.

21430420421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4885131.

The product of its (nonzero) digits is 1536, while the sum is 23.

Adding to 21430420421 its reverse (12402403412), we get a palindrome (33832823833).

The spelling of 21430420421 in words is "twenty-one billion, four hundred thirty million, four hundred twenty thousand, four hundred twenty-one".