21968968 has 32 divisors (see below), whose sum is σ = 47462400. Its totient is φ = 9338112.

The previous prime is 21968951. The next prime is 21968971. The reversal of 21968968 is 86986912.

It is a happy number.

It is a plaindrome in base 11.

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, 5568 + ... + 8656.

It is an arithmetic number, because the mean of its divisors is an integer number (1483200).

Almost surely, 2^21968968 is an apocalyptic number.

21968968 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21968968 is an abundant number, since it is smaller than the sum of its proper divisors (25493432).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21968968 is a wasteful number, since it uses less digits than its factorization.

21968968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3229 (or 3225 counting only the distinct ones).

The product of its digits is 373248, while the sum is 49.

The square root of 21968968 is about 4687.1065701560. The cubic root of 21968968 is about 280.0721242773.

The spelling of 21968968 in words is "twenty-one million, nine hundred sixty-eight thousand, nine hundred sixty-eight".