1381640568 has 128 divisors (see below), whose sum is σ = 4406814720. Its totient is φ = 350501760.

The previous prime is 1381640563. The next prime is 1381640573. The reversal of 1381640568 is 8650461831.

It is an interprime number because it is at equal distance from previous prime (1381640563) and next prime (1381640573).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1381640563) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 70771 + ... + 88157.

It is an arithmetic number, because the mean of its divisors is an integer number (34428240).

Almost surely, 2^1381640568 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 1381640568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2203407360).

1381640568 is an abundant number, since it is smaller than the sum of its proper divisors (3025174152).

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

1381640568 is a wasteful number, since it uses less digits than its factorization.

1381640568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17457 (or 17453 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 42.

The square root of 1381640568 is about 37170.4259862596. The cubic root of 1381640568 is about 1113.7772913183. Note that the first 3 decimals are identical.

The spelling of 1381640568 in words is "one billion, three hundred eighty-one million, six hundred forty thousand, five hundred sixty-eight".