21421401421 has 8 divisors (see below), whose sum is σ = 24489237440. Its totient is φ = 18355474368.

The previous prime is 21421401343. The next prime is 21421401427. The reversal of 21421401421 is 12410412412.

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

It is not a de Polignac number, because 21421401421 - 2¹⁹ = 21420877133 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21421401392 and 21421401401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21421401427) 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, 453111 + ... + 498148.

It is an arithmetic number, because the mean of its divisors is an integer number (3061154680).

Almost surely, 2^21421401421 is an apocalyptic number.

It is an amenable number.

21421401421 is a deficient number, since it is larger than the sum of its proper divisors (3067836019).

21421401421 is an equidigital number, since it uses as much as digits as its factorization.

21421401421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 954483.

The product of its (nonzero) digits is 512, while the sum is 22.

Adding to 21421401421 its reverse (12410412412), we get a palindrome (33831813833).

The spelling of 21421401421 in words is "twenty-one billion, four hundred twenty-one million, four hundred one thousand, four hundred twenty-one".