997251811 has 2 divisors, whose sum is σ = 997251812. Its totient is φ = 997251810.

The previous prime is 997251769. The next prime is 997251817. The reversal of 997251811 is 118152799.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 997251811 - 2¹¹ = 997249763 is a prime.

It is a super-2 number, since 2×997251811² = 1989022349085559442, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (997251817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498625905 + 498625906.

It is an arithmetic number, because the mean of its divisors is an integer number (498625906).

Almost surely, 2^997251811 is an apocalyptic number.

997251811 is a deficient number, since it is larger than the sum of its proper divisors (1).

997251811 is an equidigital number, since it uses as much as digits as its factorization.

997251811 is an evil number, because the sum of its binary digits is even.

The product of its digits is 45360, while the sum is 43.

The square root of 997251811 is about 31579.2940231412. The cubic root of 997251811 is about 999.0830965450.

The spelling of 997251811 in words is "nine hundred ninety-seven million, two hundred fifty-one thousand, eight hundred eleven".