21201347 has 2 divisors, whose sum is σ = 21201348. Its totient is φ = 21201346.

The previous prime is 21201311. The next prime is 21201373. The reversal of 21201347 is 74310212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21201347 - 2¹² = 21197251 is a prime.

It is a super-2 number, since 2×21201347² = 898994229228818, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21201647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600673 + 10600674.

It is an arithmetic number, because the mean of its divisors is an integer number (10600674).

Almost surely, 2^21201347 is an apocalyptic number.

21201347 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201347 is an equidigital number, since it uses as much as digits as its factorization.

21201347 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 21201347 is about 4604.4920458179. The cubic root of 21201347 is about 276.7713622892.

Adding to 21201347 its reverse (74310212), we get a palindrome (95511559).

The spelling of 21201347 in words is "twenty-one million, two hundred one thousand, three hundred forty-seven".