1538528281920 has 560 divisors, whose sum is σ = 6262212316800. Its totient is φ = 351238311936.

The previous prime is 1538528281859. The next prime is 1538528281937. The reversal of 1538528281920 is 291828258351.

1538528281920 is a `hidden beast` number, since 1 + 5 + 3 + 8 + 528 + 28 + 1 + 92 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (560).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 164561406 + ... + 164570754.

Almost surely, 2^{1538528281920} is an apocalyptic number.

1538528281920 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 1538528281920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3131106158400).

1538528281920 is an abundant number, since it is smaller than the sum of its proper divisors (4723684034880).

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

1538528281920 is an equidigital number, since it uses as much as digits as its factorization.

1538528281920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10292 (or 10273 counting only the distinct ones).

The product of its (nonzero) digits is 2764800, while the sum is 54.

The spelling of 1538528281920 in words is "one trillion, five hundred thirty-eight billion, five hundred twenty-eight million, two hundred eighty-one thousand, nine hundred twenty".