21250312 has 8 divisors (see below), whose sum is σ = 39844350. Its totient is φ = 10625152.

The previous prime is 21250309. The next prime is 21250331. The reversal of 21250312 is 21305212.

It can be written as a sum of positive squares in only one way, i.e., 20848356 + 401956 = 4566^2 + 634^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1328137 + ... + 1328152.

Almost surely, 2^21250312 is an apocalyptic number.

It is an amenable number.

21250312 is a deficient number, since it is larger than the sum of its proper divisors (18594038).

21250312 is a wasteful number, since it uses less digits than its factorization.

21250312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2656295 (or 2656291 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 21250312 is about 4609.8060696736. The cubic root of 21250312 is about 276.9842684181.

Adding to 21250312 its reverse (21305212), we get a palindrome (42555524).

The spelling of 21250312 in words is "twenty-one million, two hundred fifty thousand, three hundred twelve".