21007996 has 24 divisors (see below), whose sum is σ = 39200000. Its totient is φ = 9822384.

The previous prime is 21007967. The next prime is 21007999. The reversal of 21007996 is 69970012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21007999) by changing a digit.

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, 4255 + ... + 7753.

Almost surely, 2^21007996 is an apocalyptic number.

It is an amenable number.

21007996 is a deficient number, since it is larger than the sum of its proper divisors (18192004).

21007996 is a wasteful number, since it uses less digits than its factorization.

21007996 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3601 (or 3599 counting only the distinct ones).

The product of its (nonzero) digits is 6804, while the sum is 34.

The square root of 21007996 is about 4583.4480470493. The cubic root of 21007996 is about 275.9274296356.

The spelling of 21007996 in words is "twenty-one million, seven thousand, nine hundred ninety-six".