30891285 has 12 divisors (see below), whose sum is σ = 53544972. Its totient is φ = 16475328.

The previous prime is 30891281. The next prime is 30891307. The reversal of 30891285 is 58219803.

It can be written as a sum of positive squares in 2 ways, for example, as 8678916 + 22212369 = 2946^2 + 4713^2 .

It is not a de Polignac number, because 30891285 - 2² = 30891281 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30891281) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 343192 + ... + 343281.

It is an arithmetic number, because the mean of its divisors is an integer number (4462081).

Almost surely, 2^30891285 is an apocalyptic number.

It is an amenable number.

30891285 is a deficient number, since it is larger than the sum of its proper divisors (22653687).

30891285 is a wasteful number, since it uses less digits than its factorization.

30891285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 686484 (or 686481 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 30891285 is about 5557.9928931225. The cubic root of 30891285 is about 313.7704144852.

The spelling of 30891285 in words is "thirty million, eight hundred ninety-one thousand, two hundred eighty-five".