21190212 has 36 divisors (see below), whose sum is σ = 54048540. Its totient is φ = 6999552.

The previous prime is 21190207. The next prime is 21190217. The reversal of 21190212 is 21209112.

It is an interprime number because it is at equal distance from previous prime (21190207) and next prime (21190217).

It can be written as a sum of positive squares in 2 ways, for example, as 10536516 + 10653696 = 3246^2 + 3264^2 .

It is a tau number, because it is divible by the number of its divisors (36).

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 (21190217) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1464 + ... + 6672.

Almost surely, 2^21190212 is an apocalyptic number.

It is an amenable number.

21190212 is an abundant number, since it is smaller than the sum of its proper divisors (32858328).

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

21190212 is a wasteful number, since it uses less digits than its factorization.

21190212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5332 (or 5327 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 21190212 is about 4603.2827416964. The cubic root of 21190212 is about 276.7229001355.

Adding to 21190212 its reverse (21209112), we get a palindrome (42399324).

The spelling of 21190212 in words is "twenty-one million, one hundred ninety thousand, two hundred twelve".