821133402021 has 32 divisors (see below), whose sum is σ = 1240092685440. Its totient is φ = 536813596800.

The previous prime is 821133402007. The next prime is 821133402031. The reversal of 821133402021 is 120204331128.

821133402021 is a `hidden beast` number, since 8 + 2 + 113 + 340 + 202 + 1 = 666.

It is not a de Polignac number, because 821133402021 - 2⁹ = 821133401509 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821133402031) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2614681 + ... + 2911841.

It is an arithmetic number, because the mean of its divisors is an integer number (38752896420).

Almost surely, 2^821133402021 is an apocalyptic number.

It is an amenable number.

821133402021 is a deficient number, since it is larger than the sum of its proper divisors (418959283419).

821133402021 is a wasteful number, since it uses less digits than its factorization.

821133402021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299154 (or 299148 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

Adding to 821133402021 its reverse (120204331128), we get a palindrome (941337733149).

The spelling of 821133402021 in words is "eight hundred twenty-one billion, one hundred thirty-three million, four hundred two thousand, twenty-one".