21354201 has 18 divisors (see below), whose sum is σ = 33905690. Its totient is φ = 12941280.

The previous prime is 21354197. The next prime is 21354241. The reversal of 21354201 is 10245312.

It can be written as a sum of positive squares in only one way, i.e., 21344400 + 9801 = 4620^2 + 99^2 .

It is not a de Polignac number, because 21354201 - 2² = 21354197 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21354241) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 8716 + ... + 10893.

Almost surely, 2^21354201 is an apocalyptic number.

It is an amenable number.

21354201 is a deficient number, since it is larger than the sum of its proper divisors (12551489).

21354201 is a wasteful number, since it uses less digits than its factorization.

21354201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19637 (or 19623 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 21354201 is about 4621.0605925480. The cubic root of 21354201 is about 277.4349104705.

Adding to 21354201 its reverse (10245312), we get a palindrome (31599513).

Subtracting from 21354201 its reverse (10245312), we obtain a square (11108889 = 3333²).

It can be divided in two parts, 2135 and 4201, that added together give a palindrome (6336).

The spelling of 21354201 in words is "twenty-one million, three hundred fifty-four thousand, two hundred one".