21171084 has 24 divisors (see below), whose sum is σ = 53890368. Its totient is φ = 6415440.

The previous prime is 21171049. The next prime is 21171089. The reversal of 21171084 is 48017112.

It is not an unprimeable number, because it can be changed into a prime (21171089) 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, 80062 + ... + 80325.

It is an arithmetic number, because the mean of its divisors is an integer number (2245432).

Almost surely, 2^21171084 is an apocalyptic number.

It is an amenable number.

21171084 is an abundant number, since it is smaller than the sum of its proper divisors (32719284).

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

21171084 is a wasteful number, since it uses less digits than its factorization.

21171084 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160405 (or 160403 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 24.

The square root of 21171084 is about 4601.2046248781. The cubic root of 21171084 is about 276.6396109089.

Adding to 21171084 its reverse (48017112), we get a palindrome (69188196).

It can be divided in two parts, 2117108 and 4, that added together give a palindrome (2117112).

The spelling of 21171084 in words is "twenty-one million, one hundred seventy-one thousand, eighty-four".