1381861020 has 48 divisors (see below), whose sum is σ = 4002636960. Its totient is φ = 355789056.

The previous prime is 1381861009. The next prime is 1381861021. The reversal of 1381861020 is 201681831.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1381861021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 395347 + ... + 398826.

It is an arithmetic number, because the mean of its divisors is an integer number (83388270).

Almost surely, 2^1381861020 is an apocalyptic number.

1381861020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1381861020 is an abundant number, since it is smaller than the sum of its proper divisors (2620775940).

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

1381861020 is a wasteful number, since it uses less digits than its factorization.

1381861020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 794214 (or 794212 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 1381861020 is about 37173.3912900074. The cubic root of 1381861020 is about 1113.8365255792.

The spelling of 1381861020 in words is "one billion, three hundred eighty-one million, eight hundred sixty-one thousand, twenty".