1388731 has 4 divisors (see below), whose sum is σ = 1399464. Its totient is φ = 1378000.

The previous prime is 1388719. The next prime is 1388743. The reversal of 1388731 is 1378831.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (1388719) and next prime (1388743).

It is a cyclic number.

It is not a de Polignac number, because 1388731 - 2⁷ = 1388603 is a prime.

It is a super-2 number, since 2×1388731² = 3857147580722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1388693 and 1388702.

It is not an unprimeable number, because it can be changed into a prime (1388701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5170 + ... + 5431.

It is an arithmetic number, because the mean of its divisors is an integer number (349866).

2^1388731 is an apocalyptic number.

1388731 is a deficient number, since it is larger than the sum of its proper divisors (10733).

1388731 is a wasteful number, since it uses less digits than its factorization.

1388731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10732.

The product of its digits is 4032, while the sum is 31.

The square root of 1388731 is about 1178.4443134913. Note that the first 3 decimals coincide. The cubic root of 1388731 is about 111.5679303458.

The spelling of 1388731 in words is "one million, three hundred eighty-eight thousand, seven hundred thirty-one".