551009209 has 4 divisors (see below), whose sum is σ = 564448500. Its totient is φ = 537569920.

The previous prime is 551009191. The next prime is 551009213. The reversal of 551009209 is 902900155.

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 153884025 + 397125184 = 12405^2 + 19928^2 .

It is a cyclic number.

It is not a de Polignac number, because 551009209 - 2²⁷ = 416791481 is a prime.

It is a super-2 number, since 2×551009209² = 607222296805611362, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (551009509) 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, 6719584 + ... + 6719665.

It is an arithmetic number, because the mean of its divisors is an integer number (141112125).

Almost surely, 2^551009209 is an apocalyptic number.

It is an amenable number.

551009209 is a deficient number, since it is larger than the sum of its proper divisors (13439291).

551009209 is a wasteful number, since it uses less digits than its factorization.

551009209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13439290.

The product of its (nonzero) digits is 4050, while the sum is 31.

The square root of 551009209 is about 23473.5853460864. The cubic root of 551009209 is about 819.8220955516.

It can be divided in two parts, 55100920 and 9, that added together give a square (55100929 = 7423²).

The spelling of 551009209 in words is "five hundred fifty-one million, nine thousand, two hundred nine".