1391813256 has 128 divisors (see below), whose sum is σ = 3792821760. Its totient is φ = 423936000.

The previous prime is 1391813249. The next prime is 1391813281. The reversal of 1391813256 is 6523181931.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3470656 + ... + 3471056.

It is an arithmetic number, because the mean of its divisors is an integer number (29631420).

Almost surely, 2^1391813256 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1391813256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1896410880).

1391813256 is an abundant number, since it is smaller than the sum of its proper divisors (2401008504).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1391813256 is a wasteful number, since it uses less digits than its factorization.

1391813256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 655 (or 651 counting only the distinct ones).

The product of its digits is 38880, while the sum is 39.

The square root of 1391813256 is about 37307.0134961243. The cubic root of 1391813256 is about 1116.5041015990.

The spelling of 1391813256 in words is "one billion, three hundred ninety-one million, eight hundred thirteen thousand, two hundred fifty-six".