997809011 has 2 divisors, whose sum is σ = 997809012. Its totient is φ = 997809010.

The previous prime is 997808989. The next prime is 997809031. The reversal of 997809011 is 110908799.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-997809011 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (997809031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498904505 + 498904506.

It is an arithmetic number, because the mean of its divisors is an integer number (498904506).

Almost surely, 2^997809011 is an apocalyptic number.

997809011 is a deficient number, since it is larger than the sum of its proper divisors (1).

997809011 is an equidigital number, since it uses as much as digits as its factorization.

997809011 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40824, while the sum is 44.

The square root of 997809011 is about 31588.1150276492. The cubic root of 997809011 is about 999.2691363017.

The spelling of 997809011 in words is "nine hundred ninety-seven million, eight hundred nine thousand, eleven".