1840921 has 2 divisors, whose sum is σ = 1840922. Its totient is φ = 1840920.

The previous prime is 1840877. The next prime is 1840939. The reversal of 1840921 is 1290481.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1625625 + 215296 = 1275^2 + 464^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1840921 is a prime.

It is not a weakly prime, because it can be changed into another prime (1840961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 920460 + 920461.

It is an arithmetic number, because the mean of its divisors is an integer number (920461).

2^1840921 is an apocalyptic number.

It is an amenable number.

1840921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1840921 is an equidigital number, since it uses as much as digits as its factorization.

1840921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 1840921 is about 1356.8054392580. The cubic root of 1840921 is about 122.5589553789.

The spelling of 1840921 in words is "one million, eight hundred forty thousand, nine hundred twenty-one".