21403201 has 4 divisors (see below), whose sum is σ = 21444804. Its totient is φ = 21361600.

The previous prime is 21403199. The next prime is 21403211. The reversal of 21403201 is 10230412.

21403201 is nontrivially palindromic in base 16.

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 7535025 + 13868176 = 2745^2 + 3724^2 .

It is a cyclic number.

It is not a de Polignac number, because 21403201 - 2¹ = 21403199 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21403211) 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, 20020 + ... + 21061.

It is an arithmetic number, because the mean of its divisors is an integer number (5361201).

Almost surely, 2^21403201 is an apocalyptic number.

It is an amenable number.

21403201 is a deficient number, since it is larger than the sum of its proper divisors (41603).

21403201 is an equidigital number, since it uses as much as digits as its factorization.

21403201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41602.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 21403201 is about 4626.3593677967. The cubic root of 21403201 is about 277.6469518994.

Adding to 21403201 its reverse (10230412), we get a palindrome (31633613).

The spelling of 21403201 in words is "twenty-one million, four hundred three thousand, two hundred one".