823521404 has 12 divisors (see below), whose sum is σ = 1471825824. Its totient is φ = 402999744.

The previous prime is 823521397. The next prime is 823521409. The reversal of 823521404 is 404125328.

It is a happy number.

823521404 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×823521404² = 1356375005692262432, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (823521409) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2190029 + ... + 2190404.

It is an arithmetic number, because the mean of its divisors is an integer number (122652152).

Almost surely, 2^823521404 is an apocalyptic number.

It is an amenable number.

823521404 is a deficient number, since it is larger than the sum of its proper divisors (648304420).

823521404 is a wasteful number, since it uses less digits than its factorization.

823521404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4380484 (or 4380482 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 29.

The square root of 823521404 is about 28697.0626371411. The cubic root of 823521404 is about 937.3280861424.

The spelling of 823521404 in words is "eight hundred twenty-three million, five hundred twenty-one thousand, four hundred four".