21161248 has 36 divisors (see below), whose sum is σ = 43016022. Its totient is φ = 10241280.

The previous prime is 21161237. The next prime is 21161279. The reversal of 21161248 is 84216112.

It can be written as a sum of positive squares in only one way, i.e., 20903184 + 258064 = 4572^2 + 508^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 166561 + ... + 166687.

Almost surely, 2^21161248 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 21161248, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21508011).

21161248 is an abundant number, since it is smaller than the sum of its proper divisors (21854774).

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

21161248 is an equidigital number, since it uses as much as digits as its factorization.

21161248 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305 (or 170 counting only the distinct ones).

The product of its digits is 768, while the sum is 25.

The square root of 21161248 is about 4600.1356501738. The cubic root of 21161248 is about 276.5967623910.

It can be divided in two parts, 2116 and 1248, that added together give a square (3364 = 58²).

The spelling of 21161248 in words is "twenty-one million, one hundred sixty-one thousand, two hundred forty-eight".