21759104 has 64 divisors (see below), whose sum is σ = 47736000. Its totient is φ = 9833472.

The previous prime is 21759091. The next prime is 21759107. The reversal of 21759104 is 40195712.

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 (21759107) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55742 + ... + 56130.

It is an arithmetic number, because the mean of its divisors is an integer number (745875).

Almost surely, 2^21759104 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 21759104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23868000).

21759104 is an abundant number, since it is smaller than the sum of its proper divisors (25976896).

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

21759104 is a wasteful number, since it uses less digits than its factorization.

21759104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 445 (or 433 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 29.

The square root of 21759104 is about 4664.6654756799. The cubic root of 21759104 is about 279.1774499238.

The spelling of 21759104 in words is "twenty-one million, seven hundred fifty-nine thousand, one hundred four".