21161044 has 12 divisors (see below), whose sum is σ = 37081044. Its totient is φ = 10566464.

The previous prime is 21161033. The next prime is 21161047. The reversal of 21161044 is 44016112.

It can be written as a sum of positive squares in 2 ways, for example, as 8643600 + 12517444 = 2940^2 + 3538^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21161047) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 342 + ... + 6514.

It is an arithmetic number, because the mean of its divisors is an integer number (3090087).

Almost surely, 2^21161044 is an apocalyptic number.

It is an amenable number.

21161044 is a deficient number, since it is larger than the sum of its proper divisors (15920000).

21161044 is a wasteful number, since it uses less digits than its factorization.

21161044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7034 (or 7032 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 21161044 is about 4600.1134768612. The cubic root of 21161044 is about 276.5958735663.

Adding to 21161044 its reverse (44016112), we get a palindrome (65177156).

It can be divided in two parts, 2116 and 1044, that added together give a triangular number (3160 = T₇₉).

The spelling of 21161044 in words is "twenty-one million, one hundred sixty-one thousand, forty-four".