30149981 has 4 divisors (see below), whose sum is σ = 30202812. Its totient is φ = 30097152.

The previous prime is 30149969. The next prime is 30149989. The reversal of 30149981 is 18994103.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18994103 = 31 ⋅612713.

It can be written as a sum of positive squares in 2 ways, for example, as 22477081 + 7672900 = 4741^2 + 2770^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-30149981 is a prime.

It is a super-2 number, since 2×30149981² = 1818042708600722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30149989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25550 + ... + 26703.

It is an arithmetic number, because the mean of its divisors is an integer number (7550703).

Almost surely, 2^30149981 is an apocalyptic number.

It is an amenable number.

30149981 is a deficient number, since it is larger than the sum of its proper divisors (52831).

30149981 is an equidigital number, since it uses as much as digits as its factorization.

30149981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52830.

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 30149981 is about 5490.8998351818. The cubic root of 30149981 is about 311.2401965698.

The spelling of 30149981 in words is "thirty million, one hundred forty-nine thousand, nine hundred eighty-one".