551001001 has 4 divisors (see below), whose sum is σ = 551682900. Its totient is φ = 550319104.

The previous prime is 551000987. The next prime is 551001049. The reversal of 551001001 is 100100155.

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

It can be written as a sum of positive squares in 2 ways, for example, as 187717401 + 363283600 = 13701^2 + 19060^2 .

It is a cyclic number.

It is not a de Polignac number, because 551001001 - 2⁷ = 551000873 is a prime.

It is a Duffinian number.

551001001 is a modest number, since divided by 1001 gives 551 as remainder.

It is not an unprimeable number, because it can be changed into a prime (551001401) 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, 339736 + ... + 341353.

It is an arithmetic number, because the mean of its divisors is an integer number (137920725).

Almost surely, 2^551001001 is an apocalyptic number.

It is an amenable number.

551001001 is a deficient number, since it is larger than the sum of its proper divisors (681899).

551001001 is an equidigital number, since it uses as much as digits as its factorization.

551001001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 681898.

The product of its (nonzero) digits is 25, while the sum is 13.

The square root of 551001001 is about 23473.4105106182. The cubic root of 551001001 is about 819.8180247587.

Adding to 551001001 its reverse (100100155), we get a palindrome (651101156).

It can be divided in two parts, 55 and 1001001, that multiplied together give a palindrome (55055055).

The spelling of 551001001 in words is "five hundred fifty-one million, one thousand, one".