21431430221 has 8 divisors (see below), whose sum is σ = 21567209664. Its totient is φ = 21295703520.

The previous prime is 21431430211. The next prime is 21431430253. The reversal of 21431430221 is 12203413412.

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 21431430221 - 2²² = 21427235917 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 (21431430211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1092320 + ... + 1111766.

It is an arithmetic number, because the mean of its divisors is an integer number (2695901208).

Almost surely, 2^21431430221 is an apocalyptic number.

It is an amenable number.

21431430221 is a deficient number, since it is larger than the sum of its proper divisors (135779443).

21431430221 is a wasteful number, since it uses less digits than its factorization.

21431430221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26371.

The product of its (nonzero) digits is 1152, while the sum is 23.

Adding to 21431430221 its reverse (12203413412), we get a palindrome (33634843633).

The spelling of 21431430221 in words is "twenty-one billion, four hundred thirty-one million, four hundred thirty thousand, two hundred twenty-one".