1798921 has 2 divisors, whose sum is σ = 1798922. Its totient is φ = 1798920.

The previous prime is 1798919. The next prime is 1798931. The reversal of 1798921 is 1298971.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1729225 + 69696 = 1315^2 + 264^2 .

It is a cyclic number.

It is not a de Polignac number, because 1798921 - 2¹ = 1798919 is a prime.

It is a super-2 number, since 2×1798921² = 6472233528482, which contains 22 as substring.

Together with 1798919, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1798931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 899460 + 899461.

It is an arithmetic number, because the mean of its divisors is an integer number (899461).

2^1798921 is an apocalyptic number.

It is an amenable number.

1798921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1798921 is an equidigital number, since it uses as much as digits as its factorization.

1798921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 37.

The square root of 1798921 is about 1341.2386066618. The cubic root of 1798921 is about 121.6197287718.

The spelling of 1798921 in words is "one million, seven hundred ninety-eight thousand, nine hundred twenty-one".