1997917 has 4 divisors (see below), whose sum is σ = 2031840. Its totient is φ = 1963996.

The previous prime is 1997911. The next prime is 1997921. The reversal of 1997917 is 7197991.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 7197991 = 409 ⋅17599.

It is a cyclic number.

It is not a de Polignac number, because 1997917 - 2¹¹ = 1995869 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1997911) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16873 + ... + 16990.

It is an arithmetic number, because the mean of its divisors is an integer number (507960).

2^1997917 is an apocalyptic number.

It is an amenable number.

1997917 is a deficient number, since it is larger than the sum of its proper divisors (33923).

1997917 is an equidigital number, since it uses as much as digits as its factorization.

1997917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33922.

The product of its digits is 35721, while the sum is 43.

The square root of 1997917 is about 1413.4769188070. The cubic root of 1997917 is about 125.9483495364.

The spelling of 1997917 in words is "one million, nine hundred ninety-seven thousand, nine hundred seventeen".