21761713206 has 80 divisors (see below), whose sum is σ = 49314101760. Its totient is φ = 7172290800.

The previous prime is 21761713201. The next prime is 21761713231. The reversal of 21761713206 is 60231716712.

It is a happy number.

21761713206 is a `hidden beast` number, since 2 + 1 + 7 + 617 + 1 + 32 + 0 + 6 = 666.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21761713201) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 5550915 + ... + 5554833.

It is an arithmetic number, because the mean of its divisors is an integer number (616426272).

Almost surely, 2^21761713206 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21761713206, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24657050880).

21761713206 is an abundant number, since it is smaller than the sum of its proper divisors (27552388554).

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

21761713206 is a wasteful number, since it uses less digits than its factorization.

21761713206 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4311 (or 4302 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 36.

The spelling of 21761713206 in words is "twenty-one billion, seven hundred sixty-one million, seven hundred thirteen thousand, two hundred six".