21749152 has 24 divisors (see below), whose sum is σ = 43017156. Its totient is φ = 10824192.

The previous prime is 21749149. The next prime is 21749153. The reversal of 21749152 is 25194712.

It can be written as a sum of positive squares in 2 ways, for example, as 20757136 + 992016 = 4556^2 + 996^2 .

It is a super-2 number, since 2×21749152² = 946051225438208, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21749153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5998 + ... + 8914.

Almost surely, 2^21749152 is an apocalyptic number.

It is an amenable number.

21749152 is a deficient number, since it is larger than the sum of its proper divisors (21268004).

21749152 is a wasteful number, since it uses less digits than its factorization.

21749152 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3160 (or 3152 counting only the distinct ones).

The product of its digits is 5040, while the sum is 31.

The square root of 21749152 is about 4663.5986105153. The cubic root of 21749152 is about 279.1348808047.

The spelling of 21749152 in words is "twenty-one million, seven hundred forty-nine thousand, one hundred fifty-two".