2009551 has 4 divisors (see below), whose sum is σ = 2012400. Its totient is φ = 2006704.

The previous prime is 2009543. The next prime is 2009593. The reversal of 2009551 is 1559002.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 2009551 - 2³ = 2009543 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2009251) 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, 510 + ... + 2068.

It is an arithmetic number, because the mean of its divisors is an integer number (503100).

2^2009551 is an apocalyptic number.

2009551 is a deficient number, since it is larger than the sum of its proper divisors (2849).

2009551 is a wasteful number, since it uses less digits than its factorization.

2009551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2848.

The product of its (nonzero) digits is 450, while the sum is 22.

The square root of 2009551 is about 1417.5863289409. The cubic root of 2009551 is about 126.1923450107.

The spelling of 2009551 in words is "two million, nine thousand, five hundred fifty-one".