1386791640 has 192 divisors, whose sum is σ = 4946235840. Its totient is φ = 334863360.

The previous prime is 1386791621. The next prime is 1386791663. The reversal of 1386791640 is 461976831.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 245245 + ... + 250835.

It is an arithmetic number, because the mean of its divisors is an integer number (25761645).

Almost surely, 2^1386791640 is an apocalyptic number.

1386791640 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 1386791640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2473117920).

1386791640 is an abundant number, since it is smaller than the sum of its proper divisors (3559444200).

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

1386791640 is a wasteful number, since it uses less digits than its factorization.

1386791640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5674 (or 5667 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 1386791640 is about 37239.6514484226. The cubic root of 1386791640 is about 1115.1597135596.

The spelling of 1386791640 in words is "one billion, three hundred eighty-six million, seven hundred ninety-one thousand, six hundred forty".