21887768 has 32 divisors (see below), whose sum is σ = 48051360. Its totient is φ = 9150720.

The previous prime is 21887741. The next prime is 21887771. The reversal of 21887768 is 86778812.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2471 + ... + 7062.

It is an arithmetic number, because the mean of its divisors is an integer number (1501605).

Almost surely, 2^21887768 is an apocalyptic number.

21887768 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21887768 is an abundant number, since it is smaller than the sum of its proper divisors (26163592).

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

21887768 is a wasteful number, since it uses less digits than its factorization.

21887768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9587 (or 9583 counting only the distinct ones).

The product of its digits is 301056, while the sum is 47.

The square root of 21887768 is about 4678.4364909658. The cubic root of 21887768 is about 279.7266379673.

The spelling of 21887768 in words is "twenty-one million, eight hundred eighty-seven thousand, seven hundred sixty-eight".