1921831 has 4 divisors (see below), whose sum is σ = 2023000. Its totient is φ = 1820664.

The previous prime is 1921823. The next prime is 1921841. The reversal of 1921831 is 1381291.

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 1921831 - 2³ = 1921823 is a prime.

It is a super-2 number, since 2×1921831² = 7386868785122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1921796 and 1921805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1921841) 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, 50556 + ... + 50593.

It is an arithmetic number, because the mean of its divisors is an integer number (505750).

2^1921831 is an apocalyptic number.

1921831 is a deficient number, since it is larger than the sum of its proper divisors (101169).

1921831 is a wasteful number, since it uses less digits than its factorization.

1921831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101168.

The product of its digits is 432, while the sum is 25.

The square root of 1921831 is about 1386.3011938248. The cubic root of 1921831 is about 124.3287970099.

The spelling of 1921831 in words is "one million, nine hundred twenty-one thousand, eight hundred thirty-one".