21199288 has 64 divisors (see below), whose sum is σ = 47232000. Its totient is φ = 8812800.

The previous prime is 21199259. The next prime is 21199327. The reversal of 21199288 is 88299112.

It is a self number, because there is not a number n which added to its sum of digits gives 21199288.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51628 + ... + 52036.

It is an arithmetic number, because the mean of its divisors is an integer number (738000).

Almost surely, 2^21199288 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21199288, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23616000).

21199288 is an abundant number, since it is smaller than the sum of its proper divisors (26032712).

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

21199288 is a wasteful number, since it uses less digits than its factorization.

21199288 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 476 (or 472 counting only the distinct ones).

The product of its digits is 20736, while the sum is 40.

The square root of 21199288 is about 4604.2684543801. The cubic root of 21199288 is about 276.7624023131.

It can be divided in two parts, 2119928 and 8, that added together give a square (2119936 = 1456²).

The spelling of 21199288 in words is "twenty-one million, one hundred ninety-nine thousand, two hundred eighty-eight".