1388657 has 4 divisors (see below), whose sum is σ = 1401060. Its totient is φ = 1376256.

The previous prime is 1388641. The next prime is 1388659. The reversal of 1388657 is 7568831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7568831 = 37 ⋅204563.

It can be written as a sum of positive squares in 2 ways, for example, as 474721 + 913936 = 689^2 + 956^2 .

It is a cyclic number.

It is not a de Polignac number, because 1388657 - 2⁴ = 1388641 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1388657.

It is not an unprimeable number, because it can be changed into a prime (1388659) 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, 6032 + ... + 6257.

It is an arithmetic number, because the mean of its divisors is an integer number (350265).

2^1388657 is an apocalyptic number.

It is an amenable number.

1388657 is a deficient number, since it is larger than the sum of its proper divisors (12403).

1388657 is a wasteful number, since it uses less digits than its factorization.

1388657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12402.

The product of its digits is 40320, while the sum is 38.

The square root of 1388657 is about 1178.4129157473. The cubic root of 1388657 is about 111.5659486389.

The spelling of 1388657 in words is "one million, three hundred eighty-eight thousand, six hundred fifty-seven".