21170124 has 54 divisors (see below), whose sum is σ = 54738684. Its totient is φ = 6898320.

The previous prime is 21170119. The next prime is 21170131. The reversal of 21170124 is 42107112.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21170097 and 21170106.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 161539 + ... + 161669.

Almost surely, 2^21170124 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21170124, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27369342).

21170124 is an abundant number, since it is smaller than the sum of its proper divisors (33568560).

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

21170124 is a wasteful number, since it uses less digits than its factorization.

21170124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275 (or 203 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 18.

The square root of 21170124 is about 4601.1003031884. The cubic root of 21170124 is about 276.6354294502.

Adding to 21170124 its reverse (42107112), we get a palindrome (63277236).

The spelling of 21170124 in words is "twenty-one million, one hundred seventy thousand, one hundred twenty-four".