21143200421 has 4 divisors (see below), whose sum is σ = 24163657632. Its totient is φ = 18122743212.

The previous prime is 21143200417. The next prime is 21143200427. The reversal of 21143200421 is 12400234112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21143200421 - 2² = 21143200417 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21143200393 and 21143200402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21143200427) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1510228595 + ... + 1510228608.

It is an arithmetic number, because the mean of its divisors is an integer number (6040914408).

Almost surely, 2^21143200421 is an apocalyptic number.

It is an amenable number.

21143200421 is a deficient number, since it is larger than the sum of its proper divisors (3020457211).

21143200421 is an equidigital number, since it uses as much as digits as its factorization.

21143200421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3020457210.

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 21143200421 its reverse (12400234112), we get a palindrome (33543434533).

The spelling of 21143200421 in words is "twenty-one billion, one hundred forty-three million, two hundred thousand, four hundred twenty-one".