1921313 has 4 divisors (see below), whose sum is σ = 1962240. Its totient is φ = 1880388.

The previous prime is 1921307. The next prime is 1921319. The reversal of 1921313 is 3131291.

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: 3131291 = 293 ⋅10687.

It is an interprime number because it is at equal distance from previous prime (1921307) and next prime (1921319).

It is a cyclic number.

It is not a de Polignac number, because 1921313 - 2¹⁸ = 1659169 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1921319) 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, 20393 + ... + 20486.

It is an arithmetic number, because the mean of its divisors is an integer number (490560).

2^1921313 is an apocalyptic number.

It is an amenable number.

1921313 is a deficient number, since it is larger than the sum of its proper divisors (40927).

1921313 is an equidigital number, since it uses as much as digits as its factorization.

1921313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40926.

The product of its digits is 162, while the sum is 20.

The square root of 1921313 is about 1386.1143531470. The cubic root of 1921313 is about 124.3176257009.

The spelling of 1921313 in words is "one million, nine hundred twenty-one thousand, three hundred thirteen".