21181652 has 12 divisors (see below), whose sum is σ = 37351776. Its totient is φ = 10509720.

The previous prime is 21181651. The next prime is 21181663. The reversal of 21181652 is 25618112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21181651) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 19688 + ... + 20735.

It is an arithmetic number, because the mean of its divisors is an integer number (3112648).

Almost surely, 2^21181652 is an apocalyptic number.

It is an amenable number.

21181652 is a deficient number, since it is larger than the sum of its proper divisors (16170124).

21181652 is a wasteful number, since it uses less digits than its factorization.

21181652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40558 (or 40556 counting only the distinct ones).

The product of its digits is 960, while the sum is 26.

The square root of 21181652 is about 4602.3528765187. The cubic root of 21181652 is about 276.6856334475.

Adding to 21181652 its reverse (25618112), we get a palindrome (46799764).

The spelling of 21181652 in words is "twenty-one million, one hundred eighty-one thousand, six hundred fifty-two".