21011140 has 24 divisors (see below), whose sum is σ = 44210880. Its totient is φ = 8387808.

The previous prime is 21011083. The next prime is 21011141. The reversal of 21011140 is 4111012.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is not an unprimeable number, because it can be changed into a prime (21011141) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16569 + ... + 17791.

It is an arithmetic number, because the mean of its divisors is an integer number (1842120).

Almost surely, 2^21011140 is an apocalyptic number.

21011140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21011140 is an abundant number, since it is smaller than the sum of its proper divisors (23199740).

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

21011140 is a wasteful number, since it uses less digits than its factorization.

21011140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2091 (or 2089 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 21011140 is about 4583.7910074522. The cubic root of 21011140 is about 275.9411938005.

Adding to 21011140 its reverse (4111012), we get a palindrome (25122152).

The spelling of 21011140 in words is "twenty-one million, eleven thousand, one hundred forty".