21754044 has 144 divisors (see below), whose sum is σ = 64576512. Its totient is φ = 6120576.

The previous prime is 21754043. The next prime is 21754079. The reversal of 21754044 is 44045712.

It is a junction number, because it is equal to n+sod(n) for n = 21753999 and 21754017.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21754043) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 462829 + ... + 462875.

It is an arithmetic number, because the mean of its divisors is an integer number (448448).

Almost surely, 2^21754044 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 21754044, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32288256).

21754044 is an abundant number, since it is smaller than the sum of its proper divisors (42822468).

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

21754044 is a wasteful number, since it uses less digits than its factorization.

21754044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136 (or 131 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 27.

The square root of 21754044 is about 4664.1230687022. The cubic root of 21754044 is about 279.1558076814.

Adding to 21754044 its reverse (44045712), we get a palindrome (65799756).

The spelling of 21754044 in words is "twenty-one million, seven hundred fifty-four thousand, forty-four".