31028609 has 4 divisors (see below), whose sum is σ = 31318704. Its totient is φ = 30738516.

The previous prime is 31028603. The next prime is 31028611. The reversal of 31028609 is 90682013.

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 a cyclic number.

It is not a de Polignac number, because 31028609 - 2⁸ = 31028353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31028603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 144887 + ... + 145100.

It is an arithmetic number, because the mean of its divisors is an integer number (7829676).

Almost surely, 2^31028609 is an apocalyptic number.

It is an amenable number.

31028609 is a deficient number, since it is larger than the sum of its proper divisors (290095).

31028609 is a wasteful number, since it uses less digits than its factorization.

31028609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290094.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 31028609 is about 5570.3329343945. The cubic root of 31028609 is about 314.2346718269.

It can be divided in two parts, 3102 and 8609, that added together give a palindrome (11711).

The spelling of 31028609 in words is "thirty-one million, twenty-eight thousand, six hundred nine".