21023201 has 4 divisors (see below), whose sum is σ = 21536004. Its totient is φ = 20510400.

The previous prime is 21023183. The next prime is 21023207. The reversal of 21023201 is 10232012.

It is a happy number.

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 2739025 + 18284176 = 1655^2 + 4276^2 .

It is a cyclic number.

It is not a de Polignac number, because 21023201 - 2⁶ = 21023137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21023207) 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, 256340 + ... + 256421.

It is an arithmetic number, because the mean of its divisors is an integer number (5384001).

Almost surely, 2^21023201 is an apocalyptic number.

It is an amenable number.

21023201 is a deficient number, since it is larger than the sum of its proper divisors (512803).

21023201 is an equidigital number, since it uses as much as digits as its factorization.

21023201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 512802.

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 21023201 is about 4585.1064327887. The cubic root of 21023201 is about 275.9939831006.

Adding to 21023201 its reverse (10232012), we get a palindrome (31255213).

It can be divided in two parts, 2 and 1023201, that multiplied together give a palindrome (2046402).

The spelling of 21023201 in words is "twenty-one million, twenty-three thousand, two hundred one".