21186792 has 128 divisors (see below), whose sum is σ = 66211200. Its totient is φ = 6220800.

The previous prime is 21186769. The next prime is 21186793. The reversal of 21186792 is 29768112.

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

It is not an unprimeable number, because it can be changed into a prime (21186793) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 87792 + ... + 88032.

It is an arithmetic number, because the mean of its divisors is an integer number (517275).

Almost surely, 2^21186792 is an apocalyptic number.

21186792 is a gapful number since it is divisible by the number (22) 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 21186792, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33105600).

21186792 is an abundant number, since it is smaller than the sum of its proper divisors (45024408).

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

21186792 is a wasteful number, since it uses less digits than its factorization.

21186792 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304 (or 294 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 21186792 is about 4602.9112526748. The cubic root of 21186792 is about 276.7080120788.

The spelling of 21186792 in words is "twenty-one million, one hundred eighty-six thousand, seven hundred ninety-two".