21210192 has 30 divisors (see below), whose sum is σ = 59359482. Its totient is φ = 7070016.

The previous prime is 21210179. The next prime is 21210193. The reversal of 21210192 is 29101212.

It can be written as a sum of positive squares in only one way, i.e., 21013056 + 197136 = 4584^2 + 444^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210193) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 73503 + ... + 73790.

Almost surely, 2^21210192 is an apocalyptic number.

It is an amenable number.

21210192 is an abundant number, since it is smaller than the sum of its proper divisors (38149290).

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

21210192 is a wasteful number, since it uses less digits than its factorization.

21210192 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147307 (or 147298 counting only the distinct ones).

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

The square root of 21210192 is about 4605.4524207726. The cubic root of 21210192 is about 276.8098457300.

It can be divided in two parts, 212 and 10192, that added together give a square (10404 = 102²).

The spelling of 21210192 in words is "twenty-one million, two hundred ten thousand, one hundred ninety-two".