21071180 has 24 divisors (see below), whose sum is σ = 47653872. Its totient is φ = 7780032.

The previous prime is 21071179. The next prime is 21071191. The reversal of 21071180 is 8117012.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40262 + ... + 40781.

It is an arithmetic number, because the mean of its divisors is an integer number (1985578).

Almost surely, 2^21071180 is an apocalyptic number.

21071180 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21071180 is an abundant number, since it is smaller than the sum of its proper divisors (26582692).

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

21071180 is a wasteful number, since it uses less digits than its factorization.

21071180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81065 (or 81063 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 20.

The square root of 21071180 is about 4590.3354997211. The cubic root of 21071180 is about 276.2037807512.

Adding to 21071180 its reverse (8117012), we get a palindrome (29188192).

The spelling of 21071180 in words is "twenty-one million, seventy-one thousand, one hundred eighty".