30799981 has 4 divisors (see below), whose sum is σ = 30852000. Its totient is φ = 30747964.

The previous prime is 30799973. The next prime is 30800009. The reversal of 30799981 is 18999703.

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: 18999703 = 47 ⋅404249.

It is a cyclic number.

It is not a de Polignac number, because 30799981 - 2³ = 30799973 is a prime.

It is a super-2 number, since 2×30799981² = 1897277659200722, 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 (30793981) 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, 25111 + ... + 26308.

It is an arithmetic number, because the mean of its divisors is an integer number (7713000).

Almost surely, 2^30799981 is an apocalyptic number.

It is an amenable number.

30799981 is a deficient number, since it is larger than the sum of its proper divisors (52019).

30799981 is an equidigital number, since it uses as much as digits as its factorization.

30799981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52018.

The product of its (nonzero) digits is 122472, while the sum is 46.

The square root of 30799981 is about 5549.7730584232. The cubic root of 30799981 is about 313.4609769918.

The spelling of 30799981 in words is "thirty million, seven hundred ninety-nine thousand, nine hundred eighty-one".