21170484 has 90 divisors (see below), whose sum is σ = 58732674. Its totient is φ = 6648480.

The previous prime is 21170453. The next prime is 21170507. The reversal of 21170484 is 48407112.

It can be written as a sum of positive squares in only one way, i.e., 11696400 + 9474084 = 3420^2 + 3078^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 116874 + ... + 117054.

Almost surely, 2^21170484 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 21170484, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29366337).

21170484 is an abundant number, since it is smaller than the sum of its proper divisors (37562190).

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

21170484 is a wasteful number, since it uses less digits than its factorization.

21170484 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235 (or 205 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The square root of 21170484 is about 4601.1394240992. The cubic root of 21170484 is about 276.6369975120.

Adding to 21170484 its reverse (48407112), we get a palindrome (69577596).

The spelling of 21170484 in words is "twenty-one million, one hundred seventy thousand, four hundred eighty-four".