21071140 has 12 divisors (see below), whose sum is σ = 44249436. Its totient is φ = 8428448.

The previous prime is 21071137. The next prime is 21071179. The reversal of 21071140 is 4117012.

It can be written as a sum of positive squares in 2 ways, for example, as 5579044 + 15492096 = 2362^2 + 3936^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 526759 + ... + 526798.

It is an arithmetic number, because the mean of its divisors is an integer number (3687453).

Almost surely, 2^21071140 is an apocalyptic number.

21071140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21071140 is an abundant number, since it is smaller than the sum of its proper divisors (23178296).

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

21071140 is a wasteful number, since it uses less digits than its factorization.

21071140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1053566 (or 1053564 counting only the distinct ones).

The product of its (nonzero) digits is 56, while the sum is 16.

The square root of 21071140 is about 4590.3311427391. The cubic root of 21071140 is about 276.2036059760.

Adding to 21071140 its reverse (4117012), we get a palindrome (25188152).

The spelling of 21071140 in words is "twenty-one million, seventy-one thousand, one hundred forty".