21311201 has 4 divisors (see below), whose sum is σ = 22046100.
Its totient is φ = 20576304.
The previous prime is 21311177. The next prime is 21311219. The reversal of 21311201 is 10211312.
Adding to 21311201 its reverse (10211312), we get a palindrome (31522513).
It can be divided in two parts, 21311 and 201, that added together give a palindrome (21512).
It is a semiprime because it is the product of two primes.
It can be written as a sum of positive squares in 2 ways, for example, as 17230801 + 4080400 = 4151^2 + 2020^2
It is a cyclic number.
It is not a de Polignac number, because 21311201 - 26 = 21311137 is a prime.
It is a Duffinian number.
It is a Curzon number.
It is not an unprimeable number, because it can be changed into a prime (21311261) 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, 367406 + ... + 367463.
It is an arithmetic number, because the mean of its divisors is an integer number (5511525).
Almost surely, 221311201 is an apocalyptic number.
It is an amenable number.
21311201 is a deficient number, since it is larger than the sum of its proper divisors (734899).
21311201 is an equidigital number, since it uses as much as digits as its factorization.
21311201 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 734898.
The product of its (nonzero) digits is 12, while the sum is 11.
The square root of 21311201 is about 4616.4056364232.
The cubic root of 21311201 is about 277.2485659107.
The spelling of 21311201 in words is "twenty-one million, three hundred eleven thousand, two hundred one".