821821044 has 24 divisors (see below), whose sum is σ = 2091908448. Its totient is φ = 249036640.

The previous prime is 821821019. The next prime is 821821069. The reversal of 821821044 is 440128128.

It is an interprime number because it is at equal distance from previous prime (821821019) and next prime (821821069).

It is a super-2 number, since 2×821821044² = 1350779656722499872, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3112827 + ... + 3113090.

It is an arithmetic number, because the mean of its divisors is an integer number (87162852).

Almost surely, 2^821821044 is an apocalyptic number.

It is an amenable number.

821821044 is an abundant number, since it is smaller than the sum of its proper divisors (1270087404).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

821821044 is a wasteful number, since it uses less digits than its factorization.

821821044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6225935 (or 6225933 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 30.

The square root of 821821044 is about 28667.4213001449. The cubic root of 821821044 is about 936.6825277868.

The spelling of 821821044 in words is "eight hundred twenty-one million, eight hundred twenty-one thousand, forty-four".