21968788 has 12 divisors (see below), whose sum is σ = 40468960. Its totient is φ = 10406232.

The previous prime is 21968783. The next prime is 21968803. The reversal of 21968788 is 88786912.

It is a super-3 number, since 3×21968788³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21968783) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 144456 + ... + 144607.

Almost surely, 2^21968788 is an apocalyptic number.

It is an amenable number.

21968788 is a deficient number, since it is larger than the sum of its proper divisors (18500172).

21968788 is a wasteful number, since it uses less digits than its factorization.

21968788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289086 (or 289084 counting only the distinct ones).

The product of its digits is 387072, while the sum is 49.

The square root of 21968788 is about 4687.0873685051. The cubic root of 21968788 is about 280.0713593632.

The spelling of 21968788 in words is "twenty-one million, nine hundred sixty-eight thousand, seven hundred eighty-eight".