21323371 has 2 divisors, whose sum is σ = 21323372. Its totient is φ = 21323370.

The previous prime is 21323311. The next prime is 21323417. The reversal of 21323371 is 17332312.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21323371 - 2¹⁷ = 21192299 is a prime.

It is not a weakly prime, because it can be changed into another prime (21323311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10661685 + 10661686.

It is an arithmetic number, because the mean of its divisors is an integer number (10661686).

Almost surely, 2^21323371 is an apocalyptic number.

21323371 is a deficient number, since it is larger than the sum of its proper divisors (1).

21323371 is an equidigital number, since it uses as much as digits as its factorization.

21323371 is an evil number, because the sum of its binary digits is even.

The product of its digits is 756, while the sum is 22.

The square root of 21323371 is about 4617.7235733638. The cubic root of 21323371 is about 277.3013311675.

Adding to 21323371 its reverse (17332312), we get a palindrome (38655683).

The spelling of 21323371 in words is "twenty-one million, three hundred twenty-three thousand, three hundred seventy-one".