515515421200 has 120 divisors (see below), whose sum is σ = 1334065005000. Its totient is φ = 190305914880.

The previous prime is 515515421171. The next prime is 515515421209. The reversal of 515515421200 is 2124515515.

It can be written as a sum of positive squares in 12 ways, for example, as 196082467344 + 319432953856 = 442812^2 + 565184^2 .

It is a super-2 number, since 2×515515421200² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (515515421209) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 50689716 + ... + 50699884.

It is an arithmetic number, because the mean of its divisors is an integer number (11117208375).

Almost surely, 2^515515421200 is an apocalyptic number.

515515421200 is a gapful number since it is divisible by the number (50) 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 515515421200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (667032502500).

515515421200 is an abundant number, since it is smaller than the sum of its proper divisors (818549583800).

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

515515421200 is a wasteful number, since it uses less digits than its factorization.

515515421200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19949 (or 19938 counting only the distinct ones).

The product of its (nonzero) digits is 10000, while the sum is 31.

Adding to 515515421200 its reverse (2124515515), we get a palindrome (517639936715).

The spelling of 515515421200 in words is "five hundred fifteen billion, five hundred fifteen million, four hundred twenty-one thousand, two hundred".