997651397 has 2 divisors, whose sum is σ = 997651398. Its totient is φ = 997651396.

The previous prime is 997651357. The next prime is 997651429. The reversal of 997651397 is 793156799.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 718293601 + 279357796 = 26801^2 + 16714^2 .

It is an emirp because it is prime and its reverse (793156799) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-997651397 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (997651337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498825698 + 498825699.

It is an arithmetic number, because the mean of its divisors is an integer number (498825699).

Almost surely, 2^997651397 is an apocalyptic number.

It is an amenable number.

997651397 is a deficient number, since it is larger than the sum of its proper divisors (1).

997651397 is an equidigital number, since it uses as much as digits as its factorization.

997651397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3214890, while the sum is 56.

The square root of 997651397 is about 31585.6200983929. The cubic root of 997651397 is about 999.2165186506.

The spelling of 997651397 in words is "nine hundred ninety-seven million, six hundred fifty-one thousand, three hundred ninety-seven".