21384212 has 6 divisors (see below), whose sum is σ = 37422378. Its totient is φ = 10692104.

The previous prime is 21384179. The next prime is 21384229. The reversal of 21384212 is 21248312.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 20376196 + 1008016 = 4514^2 + 1004^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2673023 + ... + 2673030.

It is an arithmetic number, because the mean of its divisors is an integer number (6237063).

Almost surely, 2^21384212 is an apocalyptic number.

It is an amenable number.

21384212 is a deficient number, since it is larger than the sum of its proper divisors (16038166).

21384212 is a wasteful number, since it uses less digits than its factorization.

21384212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5346057 (or 5346055 counting only the distinct ones).

The product of its digits is 768, while the sum is 23.

The square root of 21384212 is about 4624.3066507315. The cubic root of 21384212 is about 277.5648177999.

The spelling of 21384212 in words is "twenty-one million, three hundred eighty-four thousand, two hundred twelve".