1921771 has 2 divisors, whose sum is σ = 1921772. Its totient is φ = 1921770.

The previous prime is 1921769. The next prime is 1921781. The reversal of 1921771 is 1771291.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1921771 - 2¹ = 1921769 is a prime.

Together with 1921769, it forms a pair of twin primes.

It is a plaindrome in base 7.

It is a zygodrome in base 7.

It is not a weakly prime, because it can be changed into another prime (1921781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 960885 + 960886.

It is an arithmetic number, because the mean of its divisors is an integer number (960886).

2^1921771 is an apocalyptic number.

1921771 is a deficient number, since it is larger than the sum of its proper divisors (1).

1921771 is an equidigital number, since it uses as much as digits as its factorization.

1921771 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 882, while the sum is 28.

The square root of 1921771 is about 1386.2795533369. The cubic root of 1921771 is about 124.3275031387.

The spelling of 1921771 in words is "one million, nine hundred twenty-one thousand, seven hundred seventy-one".