21571140 has 48 divisors (see below), whose sum is σ = 60697728. Its totient is φ = 5723904.

The previous prime is 21571139. The next prime is 21571141. The reversal of 21571140 is 4117512.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21571139) and next prime (21571141).

It is not an unprimeable number, because it can be changed into a prime (21571141) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13209 + ... + 14751.

It is an arithmetic number, because the mean of its divisors is an integer number (1264536).

Almost surely, 2^21571140 is an apocalyptic number.

21571140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21571140 is an abundant number, since it is smaller than the sum of its proper divisors (39126588).

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

21571140 is a wasteful number, since it uses less digits than its factorization.

21571140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1788 (or 1786 counting only the distinct ones).

The product of its (nonzero) digits is 280, while the sum is 21.

The square root of 21571140 is about 4644.4741360029. The cubic root of 21571140 is about 278.3712411666.

Adding to 21571140 its reverse (4117512), we get a palindrome (25688652).

The spelling of 21571140 in words is "twenty-one million, five hundred seventy-one thousand, one hundred forty".