30781369 has 4 divisors (see below), whose sum is σ = 30942720. Its totient is φ = 30620020.

The previous prime is 30781351. The next prime is 30781379. The reversal of 30781369 is 96318703.

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: 96318703 = 13 ⋅7409131.

It is a cyclic number.

It is not a de Polignac number, because 30781369 - 2⁹ = 30780857 is a prime.

It is a super-2 number, since 2×30781369² = 1894985355028322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (30781319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 80389 + ... + 80770.

It is an arithmetic number, because the mean of its divisors is an integer number (7735680).

Almost surely, 2^30781369 is an apocalyptic number.

It is an amenable number.

30781369 is a deficient number, since it is larger than the sum of its proper divisors (161351).

30781369 is a wasteful number, since it uses less digits than its factorization.

30781369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161350.

The product of its (nonzero) digits is 27216, while the sum is 37.

The square root of 30781369 is about 5548.0959797033. The cubic root of 30781369 is about 313.3978242336.

The spelling of 30781369 in words is "thirty million, seven hundred eighty-one thousand, three hundred sixty-nine".