1427821 has 2 divisors, whose sum is σ = 1427822. Its totient is φ = 1427820.

The previous prime is 1427809. The next prime is 1427843. The reversal of 1427821 is 1287241.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 972196 + 455625 = 986^2 + 675^2 .

It is a cyclic number.

It is not a de Polignac number, because 1427821 - 2¹⁷ = 1296749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1427851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 713910 + 713911.

It is an arithmetic number, because the mean of its divisors is an integer number (713911).

2^1427821 is an apocalyptic number.

It is an amenable number.

1427821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1427821 is an equidigital number, since it uses as much as digits as its factorization.

1427821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 896, while the sum is 25.

The square root of 1427821 is about 1194.9146413029. The cubic root of 1427821 is about 112.6050639899.

The spelling of 1427821 in words is "one million, four hundred twenty-seven thousand, eight hundred twenty-one".