21302371 has 2 divisors, whose sum is σ = 21302372. Its totient is φ = 21302370.

The previous prime is 21302321. The next prime is 21302387. The reversal of 21302371 is 17320312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21302371 - 2⁹ = 21301859 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21302321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10651185 + 10651186.

It is an arithmetic number, because the mean of its divisors is an integer number (10651186).

Almost surely, 2^21302371 is an apocalyptic number.

21302371 is a deficient number, since it is larger than the sum of its proper divisors (1).

21302371 is an equidigital number, since it uses as much as digits as its factorization.

21302371 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 252, while the sum is 19.

The square root of 21302371 is about 4615.4491655742. The cubic root of 21302371 is about 277.2102692575.

Adding to 21302371 its reverse (17320312), we get a palindrome (38622683).

The spelling of 21302371 in words is "twenty-one million, three hundred two thousand, three hundred seventy-one".