21140920 has 32 divisors (see below), whose sum is σ = 50072400. Its totient is φ = 8011008.

The previous prime is 21140909. The next prime is 21140921. The reversal of 21140920 is 2904112.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21140921) 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, 13149 + ... + 14668.

Almost surely, 2^21140920 is an apocalyptic number.

21140920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21140920 is an abundant number, since it is smaller than the sum of its proper divisors (28931480).

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

21140920 is a wasteful number, since it uses less digits than its factorization.

21140920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27847 (or 27843 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 21140920 is about 4597.9256192331. The cubic root of 21140920 is about 276.5081655312.

The spelling of 21140920 in words is "twenty-one million, one hundred forty thousand, nine hundred twenty".