1551009 has 4 divisors (see below), whose sum is σ = 2068016. Its totient is φ = 1034004.

The previous prime is 1551001. The next prime is 1551013. The reversal of 1551009 is 9001551.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1551009 - 2³ = 1551001 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1551001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 258499 + ... + 258504.

It is an arithmetic number, because the mean of its divisors is an integer number (517004).

2^1551009 is an apocalyptic number.

It is an amenable number.

1551009 is a deficient number, since it is larger than the sum of its proper divisors (517007).

1551009 is an equidigital number, since it uses as much as digits as its factorization.

1551009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 517006.

The product of its (nonzero) digits is 225, while the sum is 21.

The square root of 1551009 is about 1245.3951180248. The cubic root of 1551009 is about 115.7545593261.

The spelling of 1551009 in words is "one million, five hundred fifty-one thousand, nine".