21019992 has 32 divisors (see below), whose sum is σ = 60057600. Its totient is φ = 6005664.

The previous prime is 21019987. The next prime is 21019993. The reversal of 21019992 is 29991012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21019993) 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 7 ways as a sum of consecutive naturals, for example, 62392 + ... + 62727.

It is an arithmetic number, because the mean of its divisors is an integer number (1876800).

Almost surely, 2^21019992 is an apocalyptic number.

It is an amenable number.

21019992 is an abundant number, since it is smaller than the sum of its proper divisors (39037608).

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

21019992 is a wasteful number, since it uses less digits than its factorization.

21019992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125135 (or 125131 counting only the distinct ones).

The product of its (nonzero) digits is 2916, while the sum is 33.

The square root of 21019992 is about 4584.7564820828. The cubic root of 21019992 is about 275.9799397308.

It can be divided in two parts, 210 and 19992, that added together give a palindrome (20202).

The spelling of 21019992 in words is "twenty-one million, nineteen thousand, nine hundred ninety-two".