1921291 has 4 divisors (see below), whose sum is σ = 1926072. Its totient is φ = 1916512.

The previous prime is 1921277. The next prime is 1921307.

1921291 is nontrivially palindromic in base 10.

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

It is a cyclic number.

It is not a de Polignac number, because 1921291 - 2¹³ = 1913099 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1921211) 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, 1726 + ... + 2611.

It is an arithmetic number, because the mean of its divisors is an integer number (481518).

2^1921291 is an apocalyptic number.

1921291 is a deficient number, since it is larger than the sum of its proper divisors (4781).

1921291 is an equidigital number, since it uses as much as digits as its factorization.

1921291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4780.

The product of its digits is 324, while the sum is 25.

The square root of 1921291 is about 1386.1064172711. The cubic root of 1921291 is about 124.3171511993.

The spelling of 1921291 in words is "one million, nine hundred twenty-one thousand, two hundred ninety-one".