1387922640 has 240 divisors, whose sum is σ = 4906918080. Its totient is φ = 323481600.

The previous prime is 1387922623. The next prime is 1387922663. The reversal of 1387922640 is 462297831.

It is a tau number, because it is divible by the number of its divisors (240).

It is a junction number, because it is equal to n+sod(n) for n = 1387922592 and 1387922601.

It is a congruent number.

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, 769740 + ... + 771540.

It is an arithmetic number, because the mean of its divisors is an integer number (20445492).

Almost surely, 2^1387922640 is an apocalyptic number.

1387922640 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 1387922640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2453459040).

1387922640 is an abundant number, since it is smaller than the sum of its proper divisors (3518995440).

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

1387922640 is a wasteful number, since it uses less digits than its factorization.

1387922640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1862 (or 1843 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 42.

The square root of 1387922640 is about 37254.8337803298. The cubic root of 1387922640 is about 1115.4627879087.

The spelling of 1387922640 in words is "one billion, three hundred eighty-seven million, nine hundred twenty-two thousand, six hundred forty".