997121837 has 2 divisors, whose sum is σ = 997121838. Its totient is φ = 997121836.

The previous prime is 997121821. The next prime is 997121897. The reversal of 997121837 is 738121799.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 776123881 + 220997956 = 27859^2 + 14866^2 .

It is an emirp because it is prime and its reverse (738121799) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 997121837 - 2⁴ = 997121821 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 997121791 and 997121800.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (997121897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498560918 + 498560919.

It is an arithmetic number, because the mean of its divisors is an integer number (498560919).

Almost surely, 2^997121837 is an apocalyptic number.

It is an amenable number.

997121837 is a deficient number, since it is larger than the sum of its proper divisors (1).

997121837 is an equidigital number, since it uses as much as digits as its factorization.

997121837 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 190512, while the sum is 47.

The square root of 997121837 is about 31577.2360570079. The cubic root of 997121837 is about 999.0396904341.

The spelling of 997121837 in words is "nine hundred ninety-seven million, one hundred twenty-one thousand, eight hundred thirty-seven".