21142312 has 8 divisors (see below), whose sum is σ = 39641850. Its totient is φ = 10571152.

The previous prime is 21142291. The next prime is 21142343. The reversal of 21142312 is 21324112.

It can be written as a sum of positive squares in only one way, i.e., 15256836 + 5885476 = 3906^2 + 2426^2 .

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, 1321387 + ... + 1321402.

Almost surely, 2^21142312 is an apocalyptic number.

It is an amenable number.

21142312 is a deficient number, since it is larger than the sum of its proper divisors (18499538).

21142312 is a wasteful number, since it uses less digits than its factorization.

21142312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2642795 (or 2642791 counting only the distinct ones).

The product of its digits is 96, while the sum is 16.

The square root of 21142312 is about 4598.0769893511. The cubic root of 21142312 is about 276.5142341873.

Adding to 21142312 its reverse (21324112), we get a palindrome (42466424).

The spelling of 21142312 in words is "twenty-one million, one hundred forty-two thousand, three hundred twelve".