21549696 has 64 divisors (see below), whose sum is σ = 65426880. Its totient is φ = 6156288.

The previous prime is 21549677. The next prime is 21549701. The reversal of 21549696 is 69694512.

It is a happy number.

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

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1321 + ... + 6696.

It is an arithmetic number, because the mean of its divisors is an integer number (1022295).

Almost surely, 2^21549696 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 21549696, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32713440).

21549696 is an abundant number, since it is smaller than the sum of its proper divisors (43877184).

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

21549696 is an equidigital number, since it uses as much as digits as its factorization.

21549696 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8041 (or 8029 counting only the distinct ones).

The product of its digits is 116640, while the sum is 42.

The square root of 21549696 is about 4642.1650121468. The cubic root of 21549696 is about 278.2789670748.

The spelling of 21549696 in words is "twenty-one million, five hundred forty-nine thousand, six hundred ninety-six".