21522337 has 2 divisors, whose sum is σ = 21522338. Its totient is φ = 21522336.

The previous prime is 21522331. The next prime is 21522341. The reversal of 21522337 is 73322512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21446161 + 76176 = 4631^2 + 276^2 .

It is a cyclic number.

It is not a de Polignac number, because 21522337 - 2³ = 21522329 is a prime.

It is not a weakly prime, because it can be changed into another prime (21522331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10761168 + 10761169.

It is an arithmetic number, because the mean of its divisors is an integer number (10761169).

Almost surely, 2^21522337 is an apocalyptic number.

It is an amenable number.

21522337 is a deficient number, since it is larger than the sum of its proper divisors (1).

21522337 is an equidigital number, since it uses as much as digits as its factorization.

21522337 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2520, while the sum is 25.

The square root of 21522337 is about 4639.2172831201. The cubic root of 21522337 is about 278.1611516698.

Adding to 21522337 its reverse (73322512), we get a palindrome (94844849).

It can be divided in two parts, 2152 and 2337, that added together give a square (4489 = 67²).

The spelling of 21522337 in words is "twenty-one million, five hundred twenty-two thousand, three hundred thirty-seven".