1391993694 has 256 divisors, whose sum is σ = 4248115200. Its totient is φ = 326965248.

The previous prime is 1391993693. The next prime is 1391993719. The reversal of 1391993694 is 4963991931.

1391993694 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 1391993694.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1391993693) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1586784 + ... + 1587660.

It is an arithmetic number, because the mean of its divisors is an integer number (16594200).

Almost surely, 2^1391993694 is an apocalyptic number.

1391993694 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1391993694, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2124057600).

1391993694 is an abundant number, since it is smaller than the sum of its proper divisors (2856121506).

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

1391993694 is a wasteful number, since it uses less digits than its factorization.

1391993694 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 944 (or 938 counting only the distinct ones).

The product of its digits is 1417176, while the sum is 54.

The square root of 1391993694 is about 37309.4317029890. The cubic root of 1391993694 is about 1116.5523482684.

The spelling of 1391993694 in words is "one billion, three hundred ninety-one million, nine hundred ninety-three thousand, six hundred ninety-four".