821617373 has 2 divisors, whose sum is σ = 821617374. Its totient is φ = 821617372.

The previous prime is 821617367. The next prime is 821617393. The reversal of 821617373 is 373716128.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 490268164 + 331349209 = 22142^2 + 18203^2 .

It is a cyclic number.

It is not a de Polignac number, because 821617373 - 2¹⁶ = 821551837 is a prime.

It is a super-2 number, since 2×821617373² = 1350110215230842258, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (821617343) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410808686 + 410808687.

It is an arithmetic number, because the mean of its divisors is an integer number (410808687).

Almost surely, 2^821617373 is an apocalyptic number.

It is an amenable number.

821617373 is a deficient number, since it is larger than the sum of its proper divisors (1).

821617373 is an equidigital number, since it uses as much as digits as its factorization.

821617373 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 42336, while the sum is 38.

The square root of 821617373 is about 28663.8687723761. The cubic root of 821617373 is about 936.6051423955.

The spelling of 821617373 in words is "eight hundred twenty-one million, six hundred seventeen thousand, three hundred seventy-three".