21321201 has 16 divisors (see below), whose sum is σ = 31324608. Its totient is φ = 12792000.

The previous prime is 21321199. The next prime is 21321203. The reversal of 21321201 is 10212312.

It is an interprime number because it is at equal distance from previous prime (21321199) and next prime (21321203).

It is not a de Polignac number, because 21321201 - 2¹ = 21321199 is a prime.

It is a super-2 number, since 2×21321201² = 909187224164802, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21321203) 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 15 ways as a sum of consecutive naturals, for example, 135 + ... + 6531.

It is an arithmetic number, because the mean of its divisors is an integer number (1957788).

Almost surely, 2^21321201 is an apocalyptic number.

It is an amenable number.

21321201 is a deficient number, since it is larger than the sum of its proper divisors (10003407).

21321201 is a wasteful number, since it uses less digits than its factorization.

21321201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6512.

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 21321201 is about 4617.4886031262. The cubic root of 21321201 is about 277.2919242073.

Adding to 21321201 its reverse (10212312), we get a palindrome (31533513).

Subtracting from 21321201 its reverse (10212312), we obtain a square (11108889 = 3333²).

It can be divided in two parts, 2132 and 1201, that added together give a palindrome (3333).

The spelling of 21321201 in words is "twenty-one million, three hundred twenty-one thousand, two hundred one".