6551221556 has 48 divisors (see below), whose sum is σ = 12640779648. Its totient is φ = 2946048000.

The previous prime is 6551221549. The next prime is 6551221631.

6551221556 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×6551221556² = 85837007751598122272, 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 15 ways as a sum of consecutive naturals, for example, 4091156 + ... + 4092756.

It is an arithmetic number, because the mean of its divisors is an integer number (263349576).

Almost surely, 2^6551221556 is an apocalyptic number.

It is an amenable number.

6551221556 is a deficient number, since it is larger than the sum of its proper divisors (6089558092).

6551221556 is a wasteful number, since it uses less digits than its factorization.

6551221556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2552 (or 2550 counting only the distinct ones).

The product of its digits is 90000, while the sum is 38.

The square root of 6551221556 is about 80939.6167275334. The cubic root of 6551221556 is about 1871.1449379399.

The spelling of 6551221556 in words is "six billion, five hundred fifty-one million, two hundred twenty-one thousand, five hundred fifty-six".