30138257 has 4 divisors (see below), whose sum is σ = 31448640. Its totient is φ = 28827876.

The previous prime is 30138217. The next prime is 30138271. The reversal of 30138257 is 75283103.

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: 75283103 = 7 ⋅10754729.

It is a cyclic number.

It is not a de Polignac number, because 30138257 - 2⁶ = 30138193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (30138217) 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, 655157 + ... + 655202.

It is an arithmetic number, because the mean of its divisors is an integer number (7862160).

Almost surely, 2^30138257 is an apocalyptic number.

It is an amenable number.

30138257 is a deficient number, since it is larger than the sum of its proper divisors (1310383).

30138257 is a wasteful number, since it uses less digits than its factorization.

30138257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1310382.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 30138257 is about 5489.8321467965. The cubic root of 30138257 is about 311.1998488037.

The spelling of 30138257 in words is "thirty million, one hundred thirty-eight thousand, two hundred fifty-seven".