30991089 has 24 divisors (see below), whose sum is σ = 43735872. Its totient is φ = 19504800.

The previous prime is 30991067. The next prime is 30991091. The reversal of 30991089 is 98019903.

It is not a de Polignac number, because 30991089 - 2⁷ = 30990961 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30991019) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 205164 + ... + 205314.

It is an arithmetic number, because the mean of its divisors is an integer number (1822328).

Almost surely, 2^30991089 is an apocalyptic number.

It is an amenable number.

30991089 is a deficient number, since it is larger than the sum of its proper divisors (12744783).

30991089 is a wasteful number, since it uses less digits than its factorization.

30991089 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277 (or 234 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 39.

The square root of 30991089 is about 5566.9640738916. The cubic root of 30991089 is about 314.1079625234.

The spelling of 30991089 in words is "thirty million, nine hundred ninety-one thousand, eighty-nine".