2005655551 has 4 divisors (see below), whose sum is σ = 2010044752. Its totient is φ = 2001266352.

The previous prime is 2005655479. The next prime is 2005655593. The reversal of 2005655551 is 1555565002.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2005655551 - 2¹⁵ = 2005622783 is a prime.

It is a super-2 number, since 2×2005655551² = 8045308378514227202, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2005650551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2193915 + ... + 2194828.

It is an arithmetic number, because the mean of its divisors is an integer number (502511188).

Almost surely, 2^2005655551 is an apocalyptic number.

2005655551 is a deficient number, since it is larger than the sum of its proper divisors (4389201).

2005655551 is an equidigital number, since it uses as much as digits as its factorization.

2005655551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4389200.

The product of its (nonzero) digits is 37500, while the sum is 34.

The square root of 2005655551 is about 44784.5458947615. The cubic root of 2005655551 is about 1261.1075235286.

It can be divided in two parts, 200565 and 5551, that added together give a square (206116 = 454²).

The spelling of 2005655551 in words is "two billion, five million, six hundred fifty-five thousand, five hundred fifty-one".