997959181 has 2 divisors, whose sum is σ = 997959182. Its totient is φ = 997959180.

The previous prime is 997959163. The next prime is 997959191. The reversal of 997959181 is 181959799.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 860483556 + 137475625 = 29334^2 + 11725^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-997959181 is a prime.

It is a super-2 number, since 2×997959181² = 1991845053884381522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (997959191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498979590 + 498979591.

It is an arithmetic number, because the mean of its divisors is an integer number (498979591).

Almost surely, 2^997959181 is an apocalyptic number.

It is an amenable number.

997959181 is a deficient number, since it is larger than the sum of its proper divisors (1).

997959181 is an equidigital number, since it uses as much as digits as its factorization.

997959181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1837080, while the sum is 58.

The square root of 997959181 is about 31590.4919398227. The cubic root of 997959181 is about 999.3192637032.

The spelling of 997959181 in words is "nine hundred ninety-seven million, nine hundred fifty-nine thousand, one hundred eighty-one".