1391938155 has 48 divisors (see below), whose sum is σ = 2628755040. Its totient is φ = 698678784.

The previous prime is 1391938139. The next prime is 1391938193. The reversal of 1391938155 is 5518391931.

It is not a de Polignac number, because 1391938155 - 2⁴ = 1391938139 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 1391938155.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 21177 + ... + 56853.

It is an arithmetic number, because the mean of its divisors is an integer number (54765730).

Almost surely, 2^1391938155 is an apocalyptic number.

1391938155 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1391938155 is a deficient number, since it is larger than the sum of its proper divisors (1236816885).

1391938155 is a wasteful number, since it uses less digits than its factorization.

1391938155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35725 (or 35702 counting only the distinct ones).

The product of its digits is 145800, while the sum is 45.

The square root of 1391938155 is about 37308.6873931528. The cubic root of 1391938155 is about 1116.5374983386.

The spelling of 1391938155 in words is "one billion, three hundred ninety-one million, nine hundred thirty-eight thousand, one hundred fifty-five".