21864607830 has 384 divisors, whose sum is σ = 66572513280. Its totient is φ = 5126561280.

The previous prime is 21864607823. The next prime is 21864607859. The reversal of 21864607830 is 3870646812.

21864607830 is a `hidden beast` number, since 2 + 1 + 8 + 6 + 4 + 607 + 8 + 30 = 666.

It is a super-2 number, since 2×21864607830² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 81280936 + ... + 81281204.

It is an arithmetic number, because the mean of its divisors is an integer number (173365920).

Almost surely, 2^21864607830 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21864607830, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33286256640).

21864607830 is an abundant number, since it is smaller than the sum of its proper divisors (44707905450).

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

21864607830 is a wasteful number, since it uses less digits than its factorization.

21864607830 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 418 (or 406 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 45.

The spelling of 21864607830 in words is "twenty-one billion, eight hundred sixty-four million, six hundred seven thousand, eight hundred thirty".