1897213 has 4 divisors (see below), whose sum is σ = 1918620. Its totient is φ = 1875808.

The previous prime is 1897199. The next prime is 1897219. The reversal of 1897213 is 3127981.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1352569 + 544644 = 1163^2 + 738^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1897213 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

1897213 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1897219) 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, 10570 + ... + 10747.

It is an arithmetic number, because the mean of its divisors is an integer number (479655).

2^1897213 is an apocalyptic number.

It is an amenable number.

1897213 is a deficient number, since it is larger than the sum of its proper divisors (21407).

1897213 is an equidigital number, since it uses as much as digits as its factorization.

1897213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21406.

The product of its digits is 3024, while the sum is 31.

The square root of 1897213 is about 1377.3935530559. The cubic root of 1897213 is about 123.7956441494.

The spelling of 1897213 in words is "one million, eight hundred ninety-seven thousand, two hundred thirteen".