21520200 has 192 divisors, whose sum is σ = 74995200. Its totient is φ = 5068800.

The previous prime is 21520193. The next prime is 21520207. The reversal of 21520200 is 202512.

It is an interprime number because it is at equal distance from previous prime (21520193) and next prime (21520207).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21520207) 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 47 ways as a sum of consecutive naturals, for example, 241756 + ... + 241844.

It is an arithmetic number, because the mean of its divisors is an integer number (390600).

Almost surely, 2^21520200 is an apocalyptic number.

21520200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

21520200 is the 2480-th nonagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21520200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37497600).

21520200 is an abundant number, since it is smaller than the sum of its proper divisors (53475000).

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

21520200 is a wasteful number, since it uses less digits than its factorization.

21520200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152 (or 143 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 12.

The square root of 21520200 is about 4638.9869583779. The cubic root of 21520200 is about 278.1519449550.

Adding to 21520200 its reverse (202512), we get a palindrome (21722712).

The spelling of 21520200 in words is "twenty-one million, five hundred twenty thousand, two hundred".