1155997 has 2 divisors, whose sum is σ = 1155998. Its totient is φ = 1155996.

The previous prime is 1155977. The next prime is 1156009. The reversal of 1155997 is 7995511.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1125721 + 30276 = 1061^2 + 174^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1155997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1155907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 577998 + 577999.

It is an arithmetic number, because the mean of its divisors is an integer number (577999).

2^1155997 is an apocalyptic number.

It is an amenable number.

1155997 is a deficient number, since it is larger than the sum of its proper divisors (1).

1155997 is an equidigital number, since it uses as much as digits as its factorization.

1155997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14175, while the sum is 37.

The square root of 1155997 is about 1075.1730093338. The cubic root of 1155997 is about 104.9507554418.

Subtracting from 1155997 its sum of digits (37), we obtain a triangular number (1155960 = T₁₅₂₀).

The spelling of 1155997 in words is "one million, one hundred fifty-five thousand, nine hundred ninety-seven".