21203301421 has 4 divisors (see below), whose sum is σ = 21203719744. Its totient is φ = 21202883100.

The previous prime is 21203301407. The next prime is 21203301451. The reversal of 21203301421 is 12410330212.

It is a happy number.

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 a cyclic number.

It is not a de Polignac number, because 21203301421 - 2¹¹ = 21203299373 is a prime.

It is a super-2 number, since 2×21203301421² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21203301451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120645 + ... + 238666.

It is an arithmetic number, because the mean of its divisors is an integer number (5300929936).

Almost surely, 2^21203301421 is an apocalyptic number.

It is an amenable number.

21203301421 is a deficient number, since it is larger than the sum of its proper divisors (418323).

21203301421 is an equidigital number, since it uses as much as digits as its factorization.

21203301421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 418322.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21203301421 its reverse (12410330212), we get a palindrome (33613631633).

It can be divided in two parts, 21203 and 301421, that added together give a square (322624 = 568²).

The spelling of 21203301421 in words is "twenty-one billion, two hundred three million, three hundred one thousand, four hundred twenty-one".