1541821 has 2 divisors, whose sum is σ = 1541822. Its totient is φ = 1541820.

The previous prime is 1541819. The next prime is 1541863. The reversal of 1541821 is 1281451.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1071225 + 470596 = 1035^2 + 686^2 .

It is an emirp because it is prime and its reverse (1281451) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1541821 - 2¹ = 1541819 is a prime.

Together with 1541819, it forms a pair of twin primes.

1541821 is a lucky number.

It is a zygodrome in base 3.

It is a junction number, because it is equal to n+sod(n) for n = 1541792 and 1541801.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1541921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 770910 + 770911.

It is an arithmetic number, because the mean of its divisors is an integer number (770911).

2^1541821 is an apocalyptic number.

It is an amenable number.

1541821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1541821 is an equidigital number, since it uses as much as digits as its factorization.

1541821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 320, while the sum is 22.

The square root of 1541821 is about 1241.7008496413. The cubic root of 1541821 is about 115.5255342308.

The spelling of 1541821 in words is "one million, five hundred forty-one thousand, eight hundred twenty-one".