1388688442 has 4 divisors (see below), whose sum is σ = 2083032666. Its totient is φ = 694344220.

The previous prime is 1388688437. The next prime is 1388688517. The reversal of 1388688442 is 2448868831.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 1252522881 + 136165561 = 35391^2 + 11669^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1388688442.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 347172109 + ... + 347172112.

Almost surely, 2^1388688442 is an apocalyptic number.

1388688442 is a deficient number, since it is larger than the sum of its proper divisors (694344224).

1388688442 is an equidigital number, since it uses as much as digits as its factorization.

1388688442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 694344223.

The product of its digits is 2359296, while the sum is 52.

The square root of 1388688442 is about 37265.1102507426. The cubic root of 1388688442 is about 1115.6679065871.

The spelling of 1388688442 in words is "one billion, three hundred eighty-eight million, six hundred eighty-eight thousand, four hundred forty-two".