21142201 has 2 divisors, whose sum is σ = 21142202. Its totient is φ = 21142200.

The previous prime is 21142171. The next prime is 21142213. The reversal of 21142201 is 10224112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11833600 + 9308601 = 3440^2 + 3051^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21142201 is a prime.

It is not a weakly prime, because it can be changed into another prime (21142291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10571100 + 10571101.

It is an arithmetic number, because the mean of its divisors is an integer number (10571101).

Almost surely, 2^21142201 is an apocalyptic number.

It is an amenable number.

21142201 is a deficient number, since it is larger than the sum of its proper divisors (1).

21142201 is an equidigital number, since it uses as much as digits as its factorization.

21142201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 21142201 is about 4598.0649190719. The cubic root of 21142201 is about 276.5137502740.

Adding to 21142201 its reverse (10224112), we get a palindrome (31366313).

The spelling of 21142201 in words is "twenty-one million, one hundred forty-two thousand, two hundred one".