21172337 has 2 divisors, whose sum is σ = 21172338. Its totient is φ = 21172336.

The previous prime is 21172331. The next prime is 21172343. The reversal of 21172337 is 73327112.

It is a balanced prime because it is at equal distance from previous prime (21172331) and next prime (21172343).

It can be written as a sum of positive squares in only one way, i.e., 21169201 + 3136 = 4601^2 + 56^2 .

It is a cyclic number.

It is not a de Polignac number, because 21172337 - 2⁶ = 21172273 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21172331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10586168 + 10586169.

It is an arithmetic number, because the mean of its divisors is an integer number (10586169).

Almost surely, 2^21172337 is an apocalyptic number.

It is an amenable number.

21172337 is a deficient number, since it is larger than the sum of its proper divisors (1).

21172337 is an equidigital number, since it uses as much as digits as its factorization.

21172337 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1764, while the sum is 26.

The square root of 21172337 is about 4601.3407828588. The cubic root of 21172337 is about 276.6450683935.

Adding to 21172337 its reverse (73327112), we get a palindrome (94499449).

The spelling of 21172337 in words is "twenty-one million, one hundred seventy-two thousand, three hundred thirty-seven".