21200312 has 32 divisors (see below), whose sum is σ = 45601920. Its totient is φ = 9051360.

The previous prime is 21200303. The next prime is 21200329. The reversal of 21200312 is 21300212.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21200293 and 21200302.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18887 + ... + 19977.

It is an arithmetic number, because the mean of its divisors is an integer number (1425060).

Almost surely, 2^21200312 is an apocalyptic number.

It is an amenable number.

21200312 is an abundant number, since it is smaller than the sum of its proper divisors (24401608).

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

21200312 is a wasteful number, since it uses less digits than its factorization.

21200312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1451 (or 1447 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 21200312 is about 4604.3796541988. The cubic root of 21200312 is about 276.7668584398.

Adding to 21200312 its reverse (21300212), we get a palindrome (42500524).

It can be divided in two parts, 21200 and 312, that added together give a palindrome (21512).

The spelling of 21200312 in words is "twenty-one million, two hundred thousand, three hundred twelve".