21438712 has 32 divisors (see below), whose sum is σ = 41698800. Its totient is φ = 10326784.

The previous prime is 21438689. The next prime is 21438733. The reversal of 21438712 is 21783412.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24588 + ... + 25444.

Almost surely, 2^21438712 is an apocalyptic number.

It is an amenable number.

21438712 is a deficient number, since it is larger than the sum of its proper divisors (20260088).

21438712 is a wasteful number, since it uses less digits than its factorization.

21438712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 975 (or 971 counting only the distinct ones).

The product of its digits is 2688, while the sum is 28.

The square root of 21438712 is about 4630.1956762107. The cubic root of 21438712 is about 277.8004191797.

The spelling of 21438712 in words is "twenty-one million, four hundred thirty-eight thousand, seven hundred twelve".