3556203657666 has 64 divisors (see below), whose sum is σ = 7845013886976. Its totient is φ = 1065706790400.

The previous prime is 3556203657647. The next prime is 3556203657689. The reversal of 3556203657666 is 6667563026553.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8128651 + ... + 8554961.

It is an arithmetic number, because the mean of its divisors is an integer number (122578341984).

Almost surely, 2^{3556203657666} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3556203657666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3922506943488).

3556203657666 is an abundant number, since it is smaller than the sum of its proper divisors (4288810229310).

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

3556203657666 is a wasteful number, since it uses less digits than its factorization.

3556203657666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 427727.

The product of its (nonzero) digits is 122472000, while the sum is 60.

The spelling of 3556203657666 in words is "three trillion, five hundred fifty-six billion, two hundred three million, six hundred fifty-seven thousand, six hundred sixty-six".