21761152 has 64 divisors (see below), whose sum is σ = 50184000. Its totient is φ = 9206784.

The previous prime is 21761093. The next prime is 21761153. The reversal of 21761152 is 25116712.

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (21761153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 133423 + ... + 133585.

It is an arithmetic number, because the mean of its divisors is an integer number (784125).

Almost surely, 2^21761152 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 21761152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25092000).

21761152 is an abundant number, since it is smaller than the sum of its proper divisors (28422848).

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

21761152 is a wasteful number, since it uses less digits than its factorization.

21761152 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333 (or 321 counting only the distinct ones).

The product of its digits is 840, while the sum is 25.

The square root of 21761152 is about 4664.8849932233. The cubic root of 21761152 is about 279.1862085179.

Adding to 21761152 its reverse (25116712), we get a palindrome (46877864).

The spelling of 21761152 in words is "twenty-one million, seven hundred sixty-one thousand, one hundred fifty-two".