1388857 has 4 divisors (see below), whose sum is σ = 1421200. Its totient is φ = 1356516.

The previous prime is 1388837. The next prime is 1388873. The reversal of 1388857 is 7588831.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1388857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1388837) 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, 16107 + ... + 16192.

It is an arithmetic number, because the mean of its divisors is an integer number (355300).

2^1388857 is an apocalyptic number.

It is an amenable number.

1388857 is a deficient number, since it is larger than the sum of its proper divisors (32343).

1388857 is an equidigital number, since it uses as much as digits as its factorization.

1388857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32342.

The product of its digits is 53760, while the sum is 40.

The square root of 1388857 is about 1178.4977725902. The cubic root of 1388857 is about 111.5713044416.

It can be divided in two parts, 138 and 8857, that multiplied together give a triangular number (1222266 = T₁₅₆₃).

The spelling of 1388857 in words is "one million, three hundred eighty-eight thousand, eight hundred fifty-seven".