1005561055551 has 8 divisors (see below), whose sum is σ = 1443882541360. Its totient is φ = 618806803392.

The previous prime is 1005561055547. The next prime is 1005561055567. The reversal of 1005561055551 is 1555501655001.

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

It is not a de Polignac number, because 1005561055551 - 2² = 1005561055547 is a prime.

It is a super-2 number, since 2×1005561055551² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39), and also a Moran number because the ratio is a prime number: 25783616809 = 1005561055551 / (1 + 0 + 0 + 5 + 5 + 6 + 1 + 0 + 5 + 5 + 5 + 5 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1005561055571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12891808366 + ... + 12891808443.

It is an arithmetic number, because the mean of its divisors is an integer number (180485317670).

Almost surely, 2^{1005561055551} is an apocalyptic number.

1005561055551 is a deficient number, since it is larger than the sum of its proper divisors (438321485809).

1005561055551 is a wasteful number, since it uses less digits than its factorization.

1005561055551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25783616825.

The product of its (nonzero) digits is 93750, while the sum is 39.

The spelling of 1005561055551 in words is "one trillion, five billion, five hundred sixty-one million, fifty-five thousand, five hundred fifty-one".