551661009 has 16 divisors (see below), whose sum is σ = 757215360. Its totient is φ = 356987520.

The previous prime is 551661001. The next prime is 551661013. The reversal of 551661009 is 900166155.

It is not a de Polignac number, because 551661009 - 2³ = 551661001 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (551661001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43069 + ... + 54389.

It is an arithmetic number, because the mean of its divisors is an integer number (47325960).

Almost surely, 2^551661009 is an apocalyptic number.

It is an amenable number.

551661009 is a deficient number, since it is larger than the sum of its proper divisors (205554351).

551661009 is a wasteful number, since it uses less digits than its factorization.

551661009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11800.

The product of its (nonzero) digits is 8100, while the sum is 33.

The square root of 551661009 is about 23487.4649334491. The cubic root of 551661009 is about 820.1452295814.

The spelling of 551661009 in words is "five hundred fifty-one million, six hundred sixty-one thousand, nine".