21610044 has 48 divisors (see below), whose sum is σ = 56814240. Its totient is φ = 7102080.

The previous prime is 21610027. The next prime is 21610067. The reversal of 21610044 is 44001612.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21609999 and 21610026.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6514 + ... + 9254.

It is an arithmetic number, because the mean of its divisors is an integer number (1183630).

Almost surely, 2^21610044 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 21610044, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28407120).

21610044 is an abundant number, since it is smaller than the sum of its proper divisors (35204196).

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

21610044 is a wasteful number, since it uses less digits than its factorization.

21610044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2827 (or 2819 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 21610044 is about 4648.6604522163. The cubic root of 21610044 is about 278.5384901038.

Adding to 21610044 its reverse (44001612), we get a palindrome (65611656).

The spelling of 21610044 in words is "twenty-one million, six hundred ten thousand, forty-four".