5551221556 has 12 divisors (see below), whose sum is σ = 9715755168. Its totient is φ = 2775291512.

The previous prime is 5551221541. The next prime is 5551221581. The reversal of 5551221556 is 6551221555.

It is a super-2 number, since 2×5551221556² = 61632121527598122272, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38296 + ... + 112111.

It is an arithmetic number, because the mean of its divisors is an integer number (809646264).

Almost surely, 2^5551221556 is an apocalyptic number.

It is an amenable number.

5551221556 is a deficient number, since it is larger than the sum of its proper divisors (4164533612).

5551221556 is a wasteful number, since it uses less digits than its factorization.

5551221556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159638 (or 159636 counting only the distinct ones).

The product of its digits is 75000, while the sum is 37.

The square root of 5551221556 is about 74506.5202247427. The cubic root of 5551221556 is about 1770.6369393127.

Subtracting 5551221556 from its reverse (6551221555), we obtain a palindrome (999999999).

The spelling of 5551221556 in words is "five billion, five hundred fifty-one million, two hundred twenty-one thousand, five hundred fifty-six".