1997213 has 2 divisors, whose sum is σ = 1997214. Its totient is φ = 1997212.

The previous prime is 1997189. The next prime is 1997231. The reversal of 1997213 is 3127991.

It is a happy number.

Together with next prime (1997231) 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., 1800964 + 196249 = 1342^2 + 443^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1997213 is a prime.

It is equal to p₁₄₈₇₃₉ and since 1997213 and 148739 have the same sum of digits, it is a Honaker prime.

It is a plaindrome in base 11.

It is a self number, because there is not a number n which added to its sum of digits gives 1997213.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1997243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 998606 + 998607.

It is an arithmetic number, because the mean of its divisors is an integer number (998607).

2^1997213 is an apocalyptic number.

It is an amenable number.

1997213 is a deficient number, since it is larger than the sum of its proper divisors (1).

1997213 is an equidigital number, since it uses as much as digits as its factorization.

1997213 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 1997213 is about 1413.2278655617. The cubic root of 1997213 is about 125.9335544516.

The spelling of 1997213 in words is "one million, nine hundred ninety-seven thousand, two hundred thirteen".