821520041 has 2 divisors, whose sum is σ = 821520042. Its totient is φ = 821520040.

The previous prime is 821520023. The next prime is 821520059. The reversal of 821520041 is 140025128.

It is a balanced prime because it is at equal distance from previous prime (821520023) and next prime (821520059).

It can be written as a sum of positive squares in only one way, i.e., 749609641 + 71910400 = 27379^2 + 8480^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-821520041 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 821519989 and 821520016.

It is not a weakly prime, because it can be changed into another prime (821520061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410760020 + 410760021.

It is an arithmetic number, because the mean of its divisors is an integer number (410760021).

Almost surely, 2^821520041 is an apocalyptic number.

It is an amenable number.

821520041 is a deficient number, since it is larger than the sum of its proper divisors (1).

821520041 is an equidigital number, since it uses as much as digits as its factorization.

821520041 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 640, while the sum is 23.

The square root of 821520041 is about 28662.1709052193. The cubic root of 821520041 is about 936.5681563017.

Adding to 821520041 its reverse (140025128), we get a palindrome (961545169).

The spelling of 821520041 in words is "eight hundred twenty-one million, five hundred twenty thousand, forty-one".