21887488 has 80 divisors (see below), whose sum is σ = 51853824. Its totient is φ = 9031680.

The previous prime is 21887479. The next prime is 21887491. The reversal of 21887488 is 88478812.

It is a happy number.

It is a Smith number, since the sum of its digits (46) coincides with the sum of the digits of its prime factors.

It is a nude number because it is divisible by every one of its digits.

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, 111006 + ... + 111202.

Almost surely, 2^21887488 is an apocalyptic number.

21887488 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21887488, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25926912).

21887488 is an abundant number, since it is smaller than the sum of its proper divisors (29966336).

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

21887488 is an equidigital number, since it uses as much as digits as its factorization.

21887488 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 253 (or 237 counting only the distinct ones).

The product of its digits is 229376, while the sum is 46.

The square root of 21887488 is about 4678.4065663429. The cubic root of 21887488 is about 279.7254451581.

The spelling of 21887488 in words is "twenty-one million, eight hundred eighty-seven thousand, four hundred eighty-eight".