1921769 has 2 divisors, whose sum is σ = 1921770. Its totient is φ = 1921768.

The previous prime is 1921763. The next prime is 1921771. The reversal of 1921769 is 9671291.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1075369 + 846400 = 1037^2 + 920^2 .

It is a cyclic number.

It is not a de Polignac number, because 1921769 - 2¹⁶ = 1856233 is a prime.

It is a super-2 number, since 2×1921769² = 7386392178722, which contains 22 as substring.

Together with 1921771, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1921763) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 960884 + 960885.

It is an arithmetic number, because the mean of its divisors is an integer number (960885).

2^1921769 is an apocalyptic number.

It is an amenable number.

1921769 is a deficient number, since it is larger than the sum of its proper divisors (1).

1921769 is an equidigital number, since it uses as much as digits as its factorization.

1921769 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6804, while the sum is 35.

The square root of 1921769 is about 1386.2788319815. The cubic root of 1921769 is about 124.3274600092.

The spelling of 1921769 in words is "one million, nine hundred twenty-one thousand, seven hundred sixty-nine".