1538917920 has 192 divisors, whose sum is σ = 5670000000. Its totient is φ = 388758528.

The previous prime is 1538917909. The next prime is 1538917921. The reversal of 1538917920 is 297198351.

1538917920 is a `hidden beast` number, since 1 + 538 + 91 + 7 + 9 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (1538917921) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 72706 + ... + 91454.

It is an arithmetic number, because the mean of its divisors is an integer number (29531250).

Almost surely, 2^1538917920 is an apocalyptic number.

1538917920 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 1538917920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2835000000).

1538917920 is an abundant number, since it is smaller than the sum of its proper divisors (4131082080).

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

1538917920 is a wasteful number, since it uses less digits than its factorization.

1538917920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18792 (or 18778 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 45.

The square root of 1538917920 is about 39229.0443421708. The cubic root of 1538917920 is about 1154.5298136788.

The spelling of 1538917920 in words is "one billion, five hundred thirty-eight million, nine hundred seventeen thousand, nine hundred twenty".