1798721 has 2 divisors, whose sum is σ = 1798722. Its totient is φ = 1798720.

The previous prime is 1798717. The next prime is 1798723. The reversal of 1798721 is 1278971.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1537600 + 261121 = 1240^2 + 511^2 .

It is a cyclic number.

It is not a de Polignac number, because 1798721 - 2² = 1798717 is a prime.

Together with 1798723, 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 (1798723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 899360 + 899361.

It is an arithmetic number, because the mean of its divisors is an integer number (899361).

2^1798721 is an apocalyptic number.

It is an amenable number.

1798721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1798721 is an equidigital number, since it uses as much as digits as its factorization.

1798721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7056, while the sum is 35.

The square root of 1798721 is about 1341.1640466401. The cubic root of 1798721 is about 121.6152214686.

The spelling of 1798721 in words is "one million, seven hundred ninety-eight thousand, seven hundred twenty-one".