1420721 has 2 divisors, whose sum is σ = 1420722. Its totient is φ = 1420720.

The previous prime is 1420717. The next prime is 1420729. The reversal of 1420721 is 1270241.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1288225 + 132496 = 1135^2 + 364^2 .

It is a cyclic number.

It is not a de Polignac number, because 1420721 - 2² = 1420717 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1420721.

It is not a weakly prime, because it can be changed into another prime (1420729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 710360 + 710361.

It is an arithmetic number, because the mean of its divisors is an integer number (710361).

2^1420721 is an apocalyptic number.

It is an amenable number.

1420721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1420721 is an equidigital number, since it uses as much as digits as its factorization.

1420721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 112, while the sum is 17.

The square root of 1420721 is about 1191.9400152692. The cubic root of 1420721 is about 112.4181066561.

Adding to 1420721 its reverse (1270241), we get a palindrome (2690962).

The spelling of 1420721 in words is "one million, four hundred twenty thousand, seven hundred twenty-one".