21122312 has 8 divisors (see below), whose sum is σ = 39604350. Its totient is φ = 10561152.

The previous prime is 21122291. The next prime is 21122323. The reversal of 21122312 is 21322112.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 12630916 + 8491396 = 3554^2 + 2914^2 .

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, 1320137 + ... + 1320152.

Almost surely, 2^21122312 is an apocalyptic number.

It is an amenable number.

21122312 is a deficient number, since it is larger than the sum of its proper divisors (18482038).

21122312 is a wasteful number, since it uses less digits than its factorization.

21122312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2640295 (or 2640291 counting only the distinct ones).

The product of its digits is 48, while the sum is 14.

The square root of 21122312 is about 4595.9016525596. The cubic root of 21122312 is about 276.4270152582.

Adding to 21122312 its reverse (21322112), we get a palindrome (42444424).

The spelling of 21122312 in words is "twenty-one million, one hundred twenty-two thousand, three hundred twelve".