997690997 has 2 divisors, whose sum is σ = 997690998. Its totient is φ = 997690996.

The previous prime is 997690963. The next prime is 997691041. The reversal of 997690997 is 799096799.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 933546916 + 64144081 = 30554^2 + 8009^2 .

It is a cyclic number.

It is not a de Polignac number, because 997690997 - 2⁶ = 997690933 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 (997690907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498845498 + 498845499.

It is an arithmetic number, because the mean of its divisors is an integer number (498845499).

Almost surely, 2^997690997 is an apocalyptic number.

It is an amenable number.

997690997 is a deficient number, since it is larger than the sum of its proper divisors (1).

997690997 is an equidigital number, since it uses as much as digits as its factorization.

997690997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17360406, while the sum is 65.

The square root of 997690997 is about 31586.2469597133. The cubic root of 997690997 is about 999.2297391839.

The spelling of 997690997 in words is "nine hundred ninety-seven million, six hundred ninety thousand, nine hundred ninety-seven".