21515225200 has 60 divisors (see below), whose sum is σ = 59074668880. Its totient is φ = 7376647680.

The previous prime is 21515225191. The next prime is 21515225233. The reversal of 21515225200 is 252251512.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 3839205 + ... + 3844804.

Almost surely, 2^21515225200 is an apocalyptic number.

21515225200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21515225200 is an abundant number, since it is smaller than the sum of its proper divisors (37559443680).

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

21515225200 is a wasteful number, since it uses less digits than its factorization.

21515225200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7684034 (or 7684023 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 25.

Adding to 21515225200 its reverse (252251512), we get a palindrome (21767476712).

The spelling of 21515225200 in words is "twenty-one billion, five hundred fifteen million, two hundred twenty-five thousand, two hundred".