6621455551 has 16 divisors (see below), whose sum is σ = 6836659200. Its totient is φ = 6409732000.

The previous prime is 6621455507. The next prime is 6621455557. The reversal of 6621455551 is 1555541266.

It is a cyclic number.

It is not a de Polignac number, because 6621455551 - 2²¹ = 6619358399 is a prime.

It is a super-2 number, since 2×6621455551² = 87687347227737427202, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6621455557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1755870 + ... + 1759636.

It is an arithmetic number, because the mean of its divisors is an integer number (427291200).

Almost surely, 2^6621455551 is an apocalyptic number.

6621455551 is a deficient number, since it is larger than the sum of its proper divisors (215203649).

6621455551 is a wasteful number, since it uses less digits than its factorization.

6621455551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4214.

The product of its digits is 180000, while the sum is 40.

The square root of 6621455551 is about 81372.3266903436. The cubic root of 6621455551 is about 1877.8078748875.

The spelling of 6621455551 in words is "six billion, six hundred twenty-one million, four hundred fifty-five thousand, five hundred fifty-one".