1257139 has 4 divisors (see below), whose sum is σ = 1353856. Its totient is φ = 1160424.

The previous prime is 1257131. The next prime is 1257163. The reversal of 1257139 is 9317521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9317521 = 719 ⋅12959.

It is a cyclic number.

It is not a de Polignac number, because 1257139 - 2³ = 1257131 is a prime.

It is a Duffinian number.

1257139 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1257131) 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, 48339 + ... + 48364.

It is an arithmetic number, because the mean of its divisors is an integer number (338464).

2^1257139 is an apocalyptic number.

1257139 is a deficient number, since it is larger than the sum of its proper divisors (96717).

1257139 is an equidigital number, since it uses as much as digits as its factorization.

1257139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96716.

The product of its digits is 1890, while the sum is 28.

The square root of 1257139 is about 1121.2221011022. Note that the first 3 decimals coincide. The cubic root of 1257139 is about 107.9264187871.

The spelling of 1257139 in words is "one million, two hundred fifty-seven thousand, one hundred thirty-nine".