1381255920 has 480 divisors, whose sum is σ = 5445722880. Its totient is φ = 310210560.

The previous prime is 1381255873. The next prime is 1381255943. The reversal of 1381255920 is 295521831.

1381255920 is a `hidden beast` number, since 1 + 3 + 81 + 2 + 559 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

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 95 ways as a sum of consecutive naturals, for example, 10082092 + ... + 10082228.

It is an arithmetic number, because the mean of its divisors is an integer number (11345256).

Almost surely, 2^1381255920 is an apocalyptic number.

1381255920 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 1381255920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2722861440).

1381255920 is an abundant number, since it is smaller than the sum of its proper divisors (4064466960).

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

1381255920 is a wasteful number, since it uses less digits than its factorization.

1381255920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 253 (or 244 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The square root of 1381255920 is about 37165.2515126697. The cubic root of 1381255920 is about 1113.6739233898.

The spelling of 1381255920 in words is "one billion, three hundred eighty-one million, two hundred fifty-five thousand, nine hundred twenty".