212904 has 24 divisors (see below), whose sum is σ = 576810. Its totient is φ = 70944.

The previous prime is 212903. The next prime is 212909. The reversal of 212904 is 409212.

It can be written as a sum of positive squares in only one way, i.e., 202500 + 10404 = 450^2 + 102^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×212904² = 90656226432, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (212903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1407 + ... + 1550.

2²¹²⁹⁰⁴ is an apocalyptic number.

212904 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

212904 is an abundant number, since it is smaller than the sum of its proper divisors (363906).

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

212904 is a wasteful number, since it uses less digits than its factorization.

212904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2969 (or 2962 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 212904 is about 461.4152143135. The cubic root of 212904 is about 59.7119526921.

The spelling of 212904 in words is "two hundred twelve thousand, nine hundred four".