172821404 has 24 divisors (see below), whose sum is σ = 356794368. Its totient is φ = 71676720.

The previous prime is 172821391. The next prime is 172821421. The reversal of 172821404 is 404128271.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 98684 + ... + 100419.

It is an arithmetic number, because the mean of its divisors is an integer number (14866432).

Almost surely, 2^172821404 is an apocalyptic number.

172821404 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

172821404 is an abundant number, since it is smaller than the sum of its proper divisors (183972964).

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

172821404 is a wasteful number, since it uses less digits than its factorization.

172821404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199145 (or 199143 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 29.

The square root of 172821404 is about 13146.1554836386. The cubic root of 172821404 is about 557.0136564376.

Adding to 172821404 its reverse (404128271), we get a palindrome (576949675).

It can be divided in two parts, 1728 and 21404, that added together give a palindrome (23132).

The spelling of 172821404 in words is "one hundred seventy-two million, eight hundred twenty-one thousand, four hundred four".