1971213 has 4 divisors (see below), whose sum is σ = 2628288. Its totient is φ = 1314140.

The previous prime is 1971209. The next prime is 1971241. The reversal of 1971213 is 3121791.

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: 3121791 = 3 ⋅1040597.

It is a cyclic number.

It is not a de Polignac number, because 1971213 - 2² = 1971209 is a prime.

It is a D-number.

1971213 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1971253) 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, 328533 + ... + 328538.

It is an arithmetic number, because the mean of its divisors is an integer number (657072).

2^1971213 is an apocalyptic number.

It is an amenable number.

1971213 is a deficient number, since it is larger than the sum of its proper divisors (657075).

1971213 is an equidigital number, since it uses as much as digits as its factorization.

1971213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 657074.

The product of its digits is 378, while the sum is 24.

The square root of 1971213 is about 1403.9989316235. The cubic root of 1971213 is about 125.3846922140.

The spelling of 1971213 in words is "one million, nine hundred seventy-one thousand, two hundred thirteen".