821341901 has 4 divisors (see below), whose sum is σ = 836838972. Its totient is φ = 805844832.

The previous prime is 821341849. The next prime is 821341909. The reversal of 821341901 is 109143128.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 259177801 + 562164100 = 16099^2 + 23710^2 .

It is a cyclic number.

It is not a de Polignac number, because 821341901 - 2¹⁸ = 821079757 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821341909) 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 in 3 ways as a sum of consecutive naturals, for example, 7748456 + ... + 7748561.

It is an arithmetic number, because the mean of its divisors is an integer number (209209743).

Almost surely, 2^821341901 is an apocalyptic number.

It is an amenable number.

821341901 is a deficient number, since it is larger than the sum of its proper divisors (15497071).

821341901 is a wasteful number, since it uses less digits than its factorization.

821341901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15497070.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 821341901 is about 28659.0631563560. The cubic root of 821341901 is about 936.5004556558.

The spelling of 821341901 in words is "eight hundred twenty-one million, three hundred forty-one thousand, nine hundred one".