21060000 has 300 divisors, whose sum is σ = 83349882. Its totient is φ = 5184000.

The previous prime is 21059977. The next prime is 21060001. The reversal of 21060000 is 6012.

It can be written as a sum of positive squares in 5 ways, for example, as 156816 + 20903184 = 396^2 + 4572^2 .

It is a tau number, because it is divible by the number of its divisors (300).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Saint-Exupery number, since it is equal to the product of the sides of a Pythagorean triangle: 390 × 150 × 360.

It is not an unprimeable number, because it can be changed into a prime (21060001) by changing a digit.

It is a polite number, since it can be written in 49 ways as a sum of consecutive naturals, for example, 1619994 + ... + 1620006.

Almost surely, 2^21060000 is an apocalyptic number.

21060000 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 21060000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41674941).

21060000 is an abundant number, since it is smaller than the sum of its proper divisors (62289882).

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

21060000 is an equidigital number, since it uses as much as digits as its factorization.

21060000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55 (or 23 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 21060000 is about 4589.1175622335. The cubic root of 21060000 is about 276.1549224755.

Adding to 21060000 its reverse (6012), we get a palindrome (21066012).

The spelling of 21060000 in words is "twenty-one million, sixty thousand".