821253633 has 16 divisors (see below), whose sum is σ = 1107469440. Its totient is φ = 541292544.

The previous prime is 821253619. The next prime is 821253647. The reversal of 821253633 is 336352128.

It is an interprime number because it is at equal distance from previous prime (821253619) and next prime (821253647).

It is not a de Polignac number, because 821253633 - 2¹² = 821249537 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 821253594 and 821253603.

It is not an unprimeable number, because it can be changed into a prime (821253683) 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 in 15 ways as a sum of consecutive naturals, for example, 161985 + ... + 166977.

It is an arithmetic number, because the mean of its divisors is an integer number (69216840).

Almost surely, 2^821253633 is an apocalyptic number.

It is an amenable number.

821253633 is a deficient number, since it is larger than the sum of its proper divisors (286215807).

821253633 is a wasteful number, since it uses less digits than its factorization.

821253633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5608.

The product of its digits is 25920, while the sum is 33.

The square root of 821253633 is about 28657.5231483811. The cubic root of 821253633 is about 936.4669064994.

It can be divided in two parts, 82125 and 3633, that added together give a palindrome (85758).

The spelling of 821253633 in words is "eight hundred twenty-one million, two hundred fifty-three thousand, six hundred thirty-three".