21864227860 has 48 divisors (see below), whose sum is σ = 46217048976. Its totient is φ = 8688218112.

The previous prime is 21864227857. The next prime is 21864227911. The reversal of 21864227860 is 6872246812.

It can be written as a sum of positive squares in 8 ways, for example, as 4884052996 + 16980174864 = 69886^2 + 130308^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21864227860.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8430724 + ... + 8433316.

It is an arithmetic number, because the mean of its divisors is an integer number (962855187).

Almost surely, 2^21864227860 is an apocalyptic number.

21864227860 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21864227860 is an abundant number, since it is smaller than the sum of its proper divisors (24352821116).

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

21864227860 is a wasteful number, since it uses less digits than its factorization.

21864227860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5212 (or 5210 counting only the distinct ones).

The product of its (nonzero) digits is 516096, while the sum is 46.

The spelling of 21864227860 in words is "twenty-one billion, eight hundred sixty-four million, two hundred twenty-seven thousand, eight hundred sixty".