997807 has 2 divisors, whose sum is σ = 997808. Its totient is φ = 997806.

The previous prime is 997793. The next prime is 997811. The reversal of 997807 is 708799.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 997807 - 2¹⁹ = 473519 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 997807.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (997877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498903 + 498904.

It is an arithmetic number, because the mean of its divisors is an integer number (498904).

2⁹⁹⁷⁸⁰⁷ is an apocalyptic number.

997807 is a deficient number, since it is larger than the sum of its proper divisors (1).

997807 is an equidigital number, since it uses as much as digits as its factorization.

997807 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31752, while the sum is 40.

The square root of 997807 is about 998.9028981838. The cubic root of 997807 is about 99.9268464987.

The spelling of 997807 in words is "nine hundred ninety-seven thousand, eight hundred seven".