21060500 has 48 divisors (see below), whose sum is σ = 46707024. Its totient is φ = 8294400.

The previous prime is 21060491. The next prime is 21060509. The reversal of 21060500 is 506012.

It is an interprime number because it is at equal distance from previous prime (21060491) and next prime (21060509).

It can be written as a sum of positive squares in 8 ways, for example, as 1008016 + 20052484 = 1004^2 + 4478^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21060509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36212 + ... + 36788.

It is an arithmetic number, because the mean of its divisors is an integer number (973063).

Almost surely, 2^21060500 is an apocalyptic number.

21060500 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 21060500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23353512).

21060500 is an abundant number, since it is smaller than the sum of its proper divisors (25646524).

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

21060500 is a wasteful number, since it uses less digits than its factorization.

21060500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 669 (or 657 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 14.

The square root of 21060500 is about 4589.1720386144. The cubic root of 21060500 is about 276.1571079197.

Adding to 21060500 its reverse (506012), we get a palindrome (21566512).

The spelling of 21060500 in words is "twenty-one million, sixty thousand, five hundred".