3687221653566 has 128 divisors (see below), whose sum is σ = 8425634660352. Its totient is φ = 1065521184000.

The previous prime is 3687221653553. The next prime is 3687221653567. The reversal of 3687221653566 is 6653561227863.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3687221653567) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 347616235 + ... + 347626841.

It is an arithmetic number, because the mean of its divisors is an integer number (65825270784).

Almost surely, 2^{3687221653566} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3687221653566, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4212817330176).

3687221653566 is an abundant number, since it is smaller than the sum of its proper divisors (4738413006786).

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

3687221653566 is a wasteful number, since it uses less digits than its factorization.

3687221653566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13118.

The product of its digits is 65318400, while the sum is 60.

The spelling of 3687221653566 in words is "three trillion, six hundred eighty-seven billion, two hundred twenty-one million, six hundred fifty-three thousand, five hundred sixty-six".