551645551 has 4 divisors (see below), whose sum is σ = 552388752. Its totient is φ = 550902352.

The previous prime is 551645539. The next prime is 551645557. The reversal of 551645551 is 155546155.

551645551 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 551645551 - 2⁵ = 551645519 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 551645551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (551645557) 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, 370486 + ... + 371971.

It is an arithmetic number, because the mean of its divisors is an integer number (138097188).

Almost surely, 2^551645551 is an apocalyptic number.

551645551 is a deficient number, since it is larger than the sum of its proper divisors (743201).

551645551 is an equidigital number, since it uses as much as digits as its factorization.

551645551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 743200.

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

The square root of 551645551 is about 23487.1358619990. The cubic root of 551645551 is about 820.1375691261.

The spelling of 551645551 in words is "five hundred fifty-one million, six hundred forty-five thousand, five hundred fifty-one".