21081124 has 12 divisors (see below), whose sum is σ = 37257948. Its totient is φ = 10436000.

The previous prime is 21081119. The next prime is 21081131. The reversal of 21081124 is 42118012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 11778624 + 9302500 = 3432^2 + 3050^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25687 + ... + 26494.

It is an arithmetic number, because the mean of its divisors is an integer number (3104829).

Almost surely, 2^21081124 is an apocalyptic number.

It is an amenable number.

21081124 is a deficient number, since it is larger than the sum of its proper divisors (16176824).

21081124 is a wasteful number, since it uses less digits than its factorization.

21081124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52286 (or 52284 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

The square root of 21081124 is about 4591.4185171905. The cubic root of 21081124 is about 276.2472230019.

Adding to 21081124 its reverse (42118012), we get a palindrome (63199136).

The spelling of 21081124 in words is "twenty-one million, eighty-one thousand, one hundred twenty-four".