1538779140864 has 324 divisors, whose sum is σ = 5352195534504. Its totient is φ = 439650312192.

The previous prime is 1538779140841. The next prime is 1538779140881. The reversal of 1538779140864 is 4680419778351.

1538779140864 is a `hidden beast` number, since 1 + 5 + 3 + 87 + 7 + 91 + 408 + 64 = 666.

It is a tau number, because it is divible by the number of its divisors (324).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 2795784 + ... + 3300600.

Almost surely, 2^{1538779140864} is an apocalyptic number.

1538779140864 is a gapful number since it is divisible by the number (14) 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 1538779140864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2676097767252).

1538779140864 is an abundant number, since it is smaller than the sum of its proper divisors (3813416393640).

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

1538779140864 is an frugal number, since it uses more digits than its factorization.

1538779140864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 504862 (or 504829 counting only the distinct ones).

The product of its (nonzero) digits is 40642560, while the sum is 63.

The spelling of 1538779140864 in words is "one trillion, five hundred thirty-eight billion, seven hundred seventy-nine million, one hundred forty thousand, eight hundred sixty-four".