206611821648 has 240 divisors, whose sum is σ = 595193988480. Its totient is φ = 66888446976.

The previous prime is 206611821631. The next prime is 206611821649. The reversal of 206611821648 is 846128116602.

It is a happy number.

206611821648 is a `hidden beast` number, since 2 + 0 + 6 + 611 + 8 + 21 + 6 + 4 + 8 = 666.

It is a super-2 number, since 2×206611821648² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206611821649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 193275258 + ... + 193276326.

It is an arithmetic number, because the mean of its divisors is an integer number (2479974952).

Almost surely, 2^206611821648 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 206611821648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (297596994240).

206611821648 is an abundant number, since it is smaller than the sum of its proper divisors (388582166832).

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

206611821648 is a wasteful number, since it uses less digits than its factorization.

206611821648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1426 (or 1417 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 45.

The spelling of 206611821648 in words is "two hundred six billion, six hundred eleven million, eight hundred twenty-one thousand, six hundred forty-eight".