1388918231 has 2 divisors, whose sum is σ = 1388918232. Its totient is φ = 1388918230.

The previous prime is 1388918177. The next prime is 1388918263. The reversal of 1388918231 is 1328198831.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1388918231 - 2¹⁴ = 1388901847 is a prime.

It is a super-2 number, since 2×1388918231² = 3858187704808338722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1388911231) 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 as a sum of consecutive naturals, namely, 694459115 + 694459116.

It is an arithmetic number, because the mean of its divisors is an integer number (694459116).

Almost surely, 2^1388918231 is an apocalyptic number.

1388918231 is a deficient number, since it is larger than the sum of its proper divisors (1).

1388918231 is an equidigital number, since it uses as much as digits as its factorization.

1388918231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 82944, while the sum is 44.

The square root of 1388918231 is about 37268.1932886476. The cubic root of 1388918231 is about 1115.7294404454.

The spelling of 1388918231 in words is "one billion, three hundred eighty-eight million, nine hundred eighteen thousand, two hundred thirty-one".