1321997 has 2 divisors, whose sum is σ = 1321998. Its totient is φ = 1321996.

The previous prime is 1321981. The next prime is 1322003. The reversal of 1321997 is 7991231.

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., 948676 + 373321 = 974^2 + 611^2 .

It is an emirp because it is prime and its reverse (7991231) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1321997 - 2⁴ = 1321981 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1321927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660998 + 660999.

It is an arithmetic number, because the mean of its divisors is an integer number (660999).

2^1321997 is an apocalyptic number.

It is an amenable number.

1321997 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321997 is an equidigital number, since it uses as much as digits as its factorization.

1321997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3402, while the sum is 32.

The square root of 1321997 is about 1149.7812835492. The cubic root of 1321997 is about 109.7514221584.

The spelling of 1321997 in words is "one million, three hundred twenty-one thousand, nine hundred ninety-seven".