21953312 has 12 divisors (see below), whose sum is σ = 43220646. Its totient is φ = 10976640.

The previous prime is 21953311. The next prime is 21953333. The reversal of 21953312 is 21335912.

It can be written as a sum of positive squares in only one way, i.e., 21939856 + 13456 = 4684^2 + 116^2 .

It is not an unprimeable number, because it can be changed into a prime (21953311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342989 + ... + 343052.

Almost surely, 2^21953312 is an apocalyptic number.

It is an amenable number.

21953312 is a deficient number, since it is larger than the sum of its proper divisors (21267334).

21953312 is an equidigital number, since it uses as much as digits as its factorization.

21953312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 686051 (or 686043 counting only the distinct ones).

The product of its digits is 1620, while the sum is 26.

The square root of 21953312 is about 4685.4361589931. The cubic root of 21953312 is about 280.0055781202.

The spelling of 21953312 in words is "twenty-one million, nine hundred fifty-three thousand, three hundred twelve".