21199992 has 64 divisors (see below), whose sum is σ = 58354560. Its totient is φ = 6364800.

The previous prime is 21199973. The next prime is 21199999. The reversal of 21199992 is 29999112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21199999) by changing a digit.

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, 34278 + ... + 34890.

It is an arithmetic number, because the mean of its divisors is an integer number (911790).

Almost surely, 2^21199992 is an apocalyptic number.

21199992 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 21199992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29177280).

21199992 is an abundant number, since it is smaller than the sum of its proper divisors (37154568).

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

21199992 is a wasteful number, since it uses less digits than its factorization.

21199992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 764 (or 760 counting only the distinct ones).

The product of its digits is 26244, while the sum is 42.

The square root of 21199992 is about 4604.3449045440. The cubic root of 21199992 is about 276.7654659156.

The spelling of 21199992 in words is "twenty-one million, one hundred ninety-nine thousand, nine hundred ninety-two".