3556221681 has 8 divisors (see below), whose sum is σ = 4747393600. Its totient is φ = 2367932112.

The previous prime is 3556221679. The next prime is 3556221701. The reversal of 3556221681 is 1861226553.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 3556221681 - 2¹ = 3556221679 is a prime.

It is a super-2 number, since 2×3556221681² = 25293425288828931522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3556221631) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 717706 + ... + 722643.

It is an arithmetic number, because the mean of its divisors is an integer number (593424200).

Almost surely, 2^3556221681 is an apocalyptic number.

It is an amenable number.

3556221681 is a deficient number, since it is larger than the sum of its proper divisors (1191171919).

3556221681 is a wasteful number, since it uses less digits than its factorization.

3556221681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1441175.

The product of its digits is 86400, while the sum is 39.

The square root of 3556221681 is about 59634.0647700624. The cubic root of 3556221681 is about 1526.3809661965.

The spelling of 3556221681 in words is "three billion, five hundred fifty-six million, two hundred twenty-one thousand, six hundred eighty-one".