21500412216 has 32 divisors (see below), whose sum is σ = 53757302400. Its totient is φ = 7165967840.

The previous prime is 21500412211. The next prime is 21500412239. The reversal of 21500412216 is 61221400512.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21500412211) 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 7 ways as a sum of consecutive naturals, for example, 178501 + ... + 273611.

It is an arithmetic number, because the mean of its divisors is an integer number (1679915700).

Almost surely, 2^21500412216 is an apocalyptic number.

It is an amenable number.

21500412216 is an abundant number, since it is smaller than the sum of its proper divisors (32256890184).

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

21500412216 is a wasteful number, since it uses less digits than its factorization.

21500412216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104539 (or 104535 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

Adding to 21500412216 its reverse (61221400512), we get a palindrome (82721812728).

The spelling of 21500412216 in words is "twenty-one billion, five hundred million, four hundred twelve thousand, two hundred sixteen".