890509 has 4 divisors (see below), whose sum is σ = 909504. Its totient is φ = 871516.

The previous prime is 890501. The next prime is 890531. The reversal of 890509 is 905098.

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, and also an emirpimes, since its reverse is a distinct semiprime: 905098 = 2 ⋅452549.

It is a cyclic number.

It is not a de Polignac number, because 890509 - 2³ = 890501 is a prime.

It is an Ulam number.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

890509 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (890501) 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, 9427 + ... + 9520.

It is an arithmetic number, because the mean of its divisors is an integer number (227376).

2⁸⁹⁰⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

890509 is a deficient number, since it is larger than the sum of its proper divisors (18995).

890509 is a wasteful number, since it uses less digits than its factorization.

890509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18994.

The product of its (nonzero) digits is 3240, while the sum is 31.

The square root of 890509 is about 943.6678441062. The cubic root of 890509 is about 96.2083510139.

The spelling of 890509 in words is "eight hundred ninety thousand, five hundred nine".