30891393 has 12 divisors (see below), whose sum is σ = 48053460. Its totient is φ = 19010016.

The previous prime is 30891391. The next prime is 30891401. The reversal of 30891393 is 39319803.

It can be written as a sum of positive squares in 2 ways, for example, as 2663424 + 28227969 = 1632^2 + 5313^2 .

It is not a de Polignac number, because 30891393 - 2¹ = 30891391 is a prime.

It is a super-2 number, since 2×30891393² = 1908556322960898, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (30891391) 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, 131898 + ... + 132131.

It is an arithmetic number, because the mean of its divisors is an integer number (4004455).

Almost surely, 2^30891393 is an apocalyptic number.

It is an amenable number.

30891393 is a deficient number, since it is larger than the sum of its proper divisors (17162067).

30891393 is a wasteful number, since it uses less digits than its factorization.

30891393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264048 (or 264045 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 36.

The square root of 30891393 is about 5558.0026088515. The cubic root of 30891393 is about 313.7707801457.

The spelling of 30891393 in words is "thirty million, eight hundred ninety-one thousand, three hundred ninety-three".