21881530206 has 12 divisors (see below), whose sum is σ = 47409982152. Its totient is φ = 7293843396.

The previous prime is 21881530199. The next prime is 21881530213. The reversal of 21881530206 is 60203518812.

It is a happy number.

21881530206 is a `hidden beast` number, since 21 + 8 + 81 + 530 + 20 + 6 = 666.

It is an interprime number because it is at equal distance from previous prime (21881530199) and next prime (21881530213).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 607820266 + ... + 607820301.

It is an arithmetic number, because the mean of its divisors is an integer number (3950831846).

Almost surely, 2^21881530206 is an apocalyptic number.

21881530206 is an abundant number, since it is smaller than the sum of its proper divisors (25528451946).

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

21881530206 is a wasteful number, since it uses less digits than its factorization.

21881530206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1215640575 (or 1215640572 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The spelling of 21881530206 in words is "twenty-one billion, eight hundred eighty-one million, five hundred thirty thousand, two hundred six".