1388121938 has 16 divisors (see below), whose sum is σ = 2398377984. Its totient is φ = 590224320.

The previous prime is 1388121901. The next prime is 1388121941. The reversal of 1388121938 is 8391218831.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 388583 + ... + 392138.

It is an arithmetic number, because the mean of its divisors is an integer number (149898624).

Almost surely, 2^1388121938 is an apocalyptic number.

1388121938 is a deficient number, since it is larger than the sum of its proper divisors (1010256046).

1388121938 is a wasteful number, since it uses less digits than its factorization.

1388121938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 780857.

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

The square root of 1388121938 is about 37257.5084781578. The cubic root of 1388121938 is about 1115.5161767784.

The spelling of 1388121938 in words is "one billion, three hundred eighty-eight million, one hundred twenty-one thousand, nine hundred thirty-eight".