1391994240 has 512 divisors, whose sum is σ = 5658992640. Its totient is φ = 283115520.

The previous prime is 1391994217. The next prime is 1391994277. The reversal of 1391994240 is 424991931.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 1391994192 and 1391994201.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5416192 + ... + 5416448.

It is an arithmetic number, because the mean of its divisors is an integer number (11052720).

Almost surely, 2^1391994240 is an apocalyptic number.

1391994240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1391994240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2829496320).

1391994240 is an abundant number, since it is smaller than the sum of its proper divisors (4266998400).

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

1391994240 is a wasteful number, since it uses less digits than its factorization.

1391994240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 330 (or 318 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 42.

The square root of 1391994240 is about 37309.4390201729. The cubic root of 1391994240 is about 1116.5524942550.

The spelling of 1391994240 in words is "one billion, three hundred ninety-one million, nine hundred ninety-four thousand, two hundred forty".