3556881221 has 4 divisors (see below), whose sum is σ = 3558219552. Its totient is φ = 3555542892.

The previous prime is 3556881217. The next prime is 3556881247. The reversal of 3556881221 is 1221886553.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1221886553 = 7841 ⋅155833.

It is a cyclic number.

It is not a de Polignac number, because 3556881221 - 2² = 3556881217 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3556881121) 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 3 ways as a sum of consecutive naturals, for example, 665171 + ... + 670496.

It is an arithmetic number, because the mean of its divisors is an integer number (889554888).

Almost surely, 2^3556881221 is an apocalyptic number.

It is an amenable number.

3556881221 is a deficient number, since it is larger than the sum of its proper divisors (1338331).

3556881221 is a wasteful number, since it uses less digits than its factorization.

3556881221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1338330.

The product of its digits is 115200, while the sum is 41.

The square root of 3556881221 is about 59639.5944067362. The cubic root of 3556881221 is about 1526.4753216823.

The spelling of 3556881221 in words is "three billion, five hundred fifty-six million, eight hundred eighty-one thousand, two hundred twenty-one".