21321401 has 4 divisors (see below), whose sum is σ = 22443600. Its totient is φ = 20199204.

The previous prime is 21321379. The next prime is 21321407. The reversal of 21321401 is 10412312.

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 21321401 - 2⁶ = 21321337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21321407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 561071 + ... + 561108.

It is an arithmetic number, because the mean of its divisors is an integer number (5610900).

Almost surely, 2^21321401 is an apocalyptic number.

It is an amenable number.

21321401 is a deficient number, since it is larger than the sum of its proper divisors (1122199).

21321401 is a wasteful number, since it uses less digits than its factorization.

21321401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1122198.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 21321401 is about 4617.5102598695. The cubic root of 21321401 is about 277.2927912350.

Adding to 21321401 its reverse (10412312), we get a palindrome (31733713).

The spelling of 21321401 in words is "twenty-one million, three hundred twenty-one thousand, four hundred one".