21180212 has 12 divisors (see below), whose sum is σ = 39016320. Its totient is φ = 10032696.

The previous prime is 21180197. The next prime is 21180227. The reversal of 21180212 is 21208112.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21180197) and next prime (21180227).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 139268 + ... + 139419.

It is an arithmetic number, because the mean of its divisors is an integer number (3251360).

Almost surely, 2^21180212 is an apocalyptic number.

It is an amenable number.

21180212 is a deficient number, since it is larger than the sum of its proper divisors (17836108).

21180212 is a wasteful number, since it uses less digits than its factorization.

21180212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278710 (or 278708 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

The square root of 21180212 is about 4602.1964321398. The cubic root of 21180212 is about 276.6793632986.

Adding to 21180212 its reverse (21208112), we get a palindrome (42388324).

The spelling of 21180212 in words is "twenty-one million, one hundred eighty thousand, two hundred twelve".