21996508 has 6 divisors (see below), whose sum is σ = 38493896. Its totient is φ = 10998252.

The previous prime is 21996503. The next prime is 21996551. The reversal of 21996508 is 80569912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21996503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2749560 + ... + 2749567.

Almost surely, 2^21996508 is an apocalyptic number.

It is an amenable number.

21996508 is a deficient number, since it is larger than the sum of its proper divisors (16497388).

21996508 is a wasteful number, since it uses less digits than its factorization.

21996508 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5499131 (or 5499129 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 40.

The square root of 21996508 is about 4690.0434966000. The cubic root of 21996508 is about 280.1891069457.

The spelling of 21996508 in words is "twenty-one million, nine hundred ninety-six thousand, five hundred eight".