834821521 has 8 divisors (see below), whose sum is σ = 869409000. Its totient is φ = 800620800.

The previous prime is 834821509. The next prime is 834821531. The reversal of 834821521 is 125128438.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 20575296 + 814246225 = 4536^2 + 28535^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 834821521 - 2¹⁷ = 834690449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (834821531) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 92280 + ... + 100921.

It is an arithmetic number, because the mean of its divisors is an integer number (108676125).

Almost surely, 2^834821521 is an apocalyptic number.

It is an amenable number.

834821521 is a deficient number, since it is larger than the sum of its proper divisors (34587479).

834821521 is a wasteful number, since it uses less digits than its factorization.

834821521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193379.

The product of its digits is 15360, while the sum is 34.

The square root of 834821521 is about 28893.2781283121. The cubic root of 834821521 is about 941.5958710379.

Adding to 834821521 its reverse (125128438), we get a palindrome (959949959).

The spelling of 834821521 in words is "eight hundred thirty-four million, eight hundred twenty-one thousand, five hundred twenty-one".