30681919 has 4 divisors (see below), whose sum is σ = 31395496. Its totient is φ = 29968344.

The previous prime is 30681907. The next prime is 30681961. The reversal of 30681919 is 91918603.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-30681919 is a prime.

It is a super-2 number, since 2×30681919² = 1882760307045122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30681319) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 356724 + ... + 356809.

It is an arithmetic number, because the mean of its divisors is an integer number (7848874).

Almost surely, 2^30681919 is an apocalyptic number.

30681919 is a deficient number, since it is larger than the sum of its proper divisors (713577).

30681919 is an equidigital number, since it uses as much as digits as its factorization.

30681919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 713576.

The product of its (nonzero) digits is 11664, while the sum is 37.

The square root of 30681919 is about 5539.1261946267. The cubic root of 30681919 is about 313.0599462600.

The spelling of 30681919 in words is "thirty million, six hundred eighty-one thousand, nine hundred nineteen".