21094992 has 100 divisors (see below), whose sum is σ = 62701716. Its totient is φ = 6842880.

The previous prime is 21094937. The next prime is 21094999. The reversal of 21094992 is 29949012.

It can be written as a sum of positive squares in 2 ways, for example, as 6533136 + 14561856 = 2556^2 + 3816^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21094999) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 52938 + ... + 53334.

Almost surely, 2^21094992 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 21094992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31350858).

21094992 is an abundant number, since it is smaller than the sum of its proper divisors (41606724).

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

21094992 is a wasteful number, since it uses less digits than its factorization.

21094992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 458 (or 443 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 21094992 is about 4592.9284775620. The cubic root of 21094992 is about 276.3077851860.

The spelling of 21094992 in words is "twenty-one million, ninety-four thousand, nine hundred ninety-two".