21292488 has 96 divisors (see below), whose sum is σ = 66830400. Its totient is φ = 5998464.

The previous prime is 21292487. The next prime is 21292507. The reversal of 21292488 is 88429212.

It is a Harshad number since it is a multiple of its sum of digits (36).

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

It is not an unprimeable number, because it can be changed into a prime (21292487) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 41578 + ... + 42086.

It is an arithmetic number, because the mean of its divisors is an integer number (696150).

Almost surely, 2^21292488 is an apocalyptic number.

21292488 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 21292488, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33415200).

21292488 is an abundant number, since it is smaller than the sum of its proper divisors (45537912).

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

21292488 is a wasteful number, since it uses less digits than its factorization.

21292488 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 611 (or 604 counting only the distinct ones).

The product of its digits is 18432, while the sum is 36.

The square root of 21292488 is about 4614.3783980077. The cubic root of 21292488 is about 277.1673930775.

The spelling of 21292488 in words is "twenty-one million, two hundred ninety-two thousand, four hundred eighty-eight".