21320312421 has 8 divisors (see below), whose sum is σ = 28483600320. Its totient is φ = 14185283072.

The previous prime is 21320312411. The next prime is 21320312437. The reversal of 21320312421 is 12421302312.

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 21320312421 - 2¹⁷ = 21320181349 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21320312411) 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, 7062876 + ... + 7065893.

It is an arithmetic number, because the mean of its divisors is an integer number (3560450040).

Almost surely, 2^21320312421 is an apocalyptic number.

It is an amenable number.

21320312421 is a deficient number, since it is larger than the sum of its proper divisors (7163287899).

21320312421 is a wasteful number, since it uses less digits than its factorization.

21320312421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14129275.

The product of its (nonzero) digits is 576, while the sum is 21.

Adding to 21320312421 its reverse (12421302312), we get a palindrome (33741614733).

The spelling of 21320312421 in words is "twenty-one billion, three hundred twenty million, three hundred twelve thousand, four hundred twenty-one".