1388820131 has 4 divisors (see below), whose sum is σ = 1388894712. Its totient is φ = 1388745552.

The previous prime is 1388820127. The next prime is 1388820163. The reversal of 1388820131 is 1310288831.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1310288831 = 1291 ⋅1014941.

It is a cyclic number.

It is not a de Polignac number, because 1388820131 - 2² = 1388820127 is a prime.

It is a super-2 number, since 2×1388820131² = 3857642712541714322, 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 = 1388820091 and 1388820100.

It is not an unprimeable number, because it can be changed into a prime (1388820031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16676 + ... + 55278.

It is an arithmetic number, because the mean of its divisors is an integer number (347223678).

Almost surely, 2^1388820131 is an apocalyptic number.

1388820131 is a deficient number, since it is larger than the sum of its proper divisors (74581).

1388820131 is an equidigital number, since it uses as much as digits as its factorization.

1388820131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74580.

The product of its (nonzero) digits is 9216, while the sum is 35.

The square root of 1388820131 is about 37266.8771296979. The cubic root of 1388820131 is about 1115.7031716479.

The spelling of 1388820131 in words is "one billion, three hundred eighty-eight million, eight hundred twenty thousand, one hundred thirty-one".