21864245100 has 72 divisors (see below), whose sum is σ = 63685246800. Its totient is φ = 5791322880.

The previous prime is 21864245089. The next prime is 21864245107. The reversal of 21864245100 is 154246812.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21864245107) 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, 199867 + ... + 289266.

Almost surely, 2^21864245100 is an apocalyptic number.

21864245100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21864245100 is an abundant number, since it is smaller than the sum of its proper divisors (41821001700).

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

21864245100 is a wasteful number, since it uses less digits than its factorization.

21864245100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 489299 (or 489292 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 33.

The spelling of 21864245100 in words is "twenty-one billion, eight hundred sixty-four million, two hundred forty-five thousand, one hundred".