21006060 has 48 divisors (see below), whose sum is σ = 59657472. Its totient is φ = 5521600.

The previous prime is 21006053. The next prime is 21006071. The reversal of 21006060 is 6060012.

It is a Harshad number since it is a multiple of its sum of digits (15).

21006060 is a modest number, since divided by 6060 gives 2100 as remainder.

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, 1795 + ... + 6725.

It is an arithmetic number, because the mean of its divisors is an integer number (1242864).

Almost surely, 2^21006060 is an apocalyptic number.

21006060 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 21006060, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29828736).

21006060 is an abundant number, since it is smaller than the sum of its proper divisors (38651412).

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

21006060 is a wasteful number, since it uses less digits than its factorization.

21006060 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5014 (or 5012 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 21006060 is about 4583.2368474693. The cubic root of 21006060 is about 275.9189533088.

Adding to 21006060 its reverse (6060012), we get a palindrome (27066072).

The spelling of 21006060 in words is "twenty-one million, six thousand, sixty".