1381815808 has 40 divisors (see below), whose sum is σ = 2768606280. Its totient is φ = 688988160.

The previous prime is 1381815769. The next prime is 1381815817. The reversal of 1381815808 is 8085181831.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 190488 + ... + 197608.

It is an arithmetic number, because the mean of its divisors is an integer number (69215157).

Almost surely, 2^1381815808 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 1381815808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1384303140).

1381815808 is an abundant number, since it is smaller than the sum of its proper divisors (1386790472).

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

1381815808 is an frugal number, since it uses more digits than its factorization.

1381815808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7518 (or 7502 counting only the distinct ones).

The product of its (nonzero) digits is 61440, while the sum is 43.

The square root of 1381815808 is about 37172.7831618780. The cubic root of 1381815808 is about 1113.8243778727.

The spelling of 1381815808 in words is "one billion, three hundred eighty-one million, eight hundred fifteen thousand, eight hundred eight".