21144060 has 144 divisors (see below), whose sum is σ = 74483136. Its totient is φ = 4755456.

The previous prime is 21144059. The next prime is 21144083. The reversal of 21144060 is 6044112.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 122134 + ... + 122306.

It is an arithmetic number, because the mean of its divisors is an integer number (517244).

Almost surely, 2^21144060 is an apocalyptic number.

21144060 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21144060, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37241568).

21144060 is an abundant number, since it is smaller than the sum of its proper divisors (53339076).

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

21144060 is a wasteful number, since it uses less digits than its factorization.

21144060 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292 (or 287 counting only the distinct ones).

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

The square root of 21144060 is about 4598.2670648843. The cubic root of 21144060 is about 276.5218545075.

Adding to 21144060 its reverse (6044112), we get a palindrome (27188172).

The spelling of 21144060 in words is "twenty-one million, one hundred forty-four thousand, sixty".