1656997 has 2 divisors, whose sum is σ = 1656998. Its totient is φ = 1656996.

The previous prime is 1656979. The next prime is 1657001. The reversal of 1656997 is 7996561.

Together with previous prime (1656979) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1425636 + 231361 = 1194^2 + 481^2 .

It is a cyclic number.

It is not a de Polignac number, because 1656997 - 2⁷ = 1656869 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1656917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 828498 + 828499.

It is an arithmetic number, because the mean of its divisors is an integer number (828499).

2^1656997 is an apocalyptic number.

It is an amenable number.

1656997 is a deficient number, since it is larger than the sum of its proper divisors (1).

1656997 is an equidigital number, since it uses as much as digits as its factorization.

1656997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 102060, while the sum is 43.

The square root of 1656997 is about 1287.2439551227. The cubic root of 1656997 is about 118.3333721263. Note that the first 4 decimals are identical.

The spelling of 1656997 in words is "one million, six hundred fifty-six thousand, nine hundred ninety-seven".