21014424421 has 16 divisors (see below), whose sum is σ = 23598632448. Its totient is φ = 18608198400.

The previous prime is 21014424413. The next prime is 21014424427. The reversal of 21014424421 is 12442441012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21014424421 - 2³ = 21014424413 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 (21014424427) 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, 416685 + ... + 464386.

It is an arithmetic number, because the mean of its divisors is an integer number (1474914528).

Almost surely, 2^21014424421 is an apocalyptic number.

It is an amenable number.

21014424421 is a deficient number, since it is larger than the sum of its proper divisors (2584208027).

21014424421 is a wasteful number, since it uses less digits than its factorization.

21014424421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 881172.

The product of its (nonzero) digits is 2048, while the sum is 25.

Adding to 21014424421 its reverse (12442441012), we get a palindrome (33456865433).

The spelling of 21014424421 in words is "twenty-one billion, fourteen million, four hundred twenty-four thousand, four hundred twenty-one".