15138257 has 4 divisors (see below), whose sum is σ = 15146496. Its totient is φ = 15130020.

The previous prime is 15138241. The next prime is 15138259. The reversal of 15138257 is 75283151.

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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 75283151 = 2269 ⋅33179.

It is a cyclic number.

It is not a de Polignac number, because 15138257 - 2⁴ = 15138241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15138259) 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, 32 + ... + 5502.

It is an arithmetic number, because the mean of its divisors is an integer number (3786624).

Almost surely, 2^15138257 is an apocalyptic number.

It is an amenable number.

15138257 is a deficient number, since it is larger than the sum of its proper divisors (8239).

15138257 is an equidigital number, since it uses as much as digits as its factorization.

15138257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8238.

The product of its digits is 8400, while the sum is 32.

The square root of 15138257 is about 3890.7913076905. The cubic root of 15138257 is about 247.3766048161.

The spelling of 15138257 in words is "fifteen million, one hundred thirty-eight thousand, two hundred fifty-seven".