1578139531457 has 4 divisors (see below), whose sum is σ = 1632558136020. Its totient is φ = 1523720926896.

The previous prime is 1578139531411. The next prime is 1578139531471. The reversal of 1578139531457 is 7541359318751.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 665740133041 + 912399398416 = 815929^2 + 955196^2 .

It is a cyclic number.

It is not a de Polignac number, because 1578139531457 - 2¹⁰ = 1578139530433 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1578139531396 and 1578139531405.

It is not an unprimeable number, because it can be changed into a prime (1578139531487) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27209302238 + ... + 27209302295.

It is an arithmetic number, because the mean of its divisors is an integer number (408139534005).

Almost surely, 2^{1578139531457} is an apocalyptic number.

It is an amenable number.

1578139531457 is a deficient number, since it is larger than the sum of its proper divisors (54418604563).

1578139531457 is an equidigital number, since it uses as much as digits as its factorization.

1578139531457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54418604562.

The product of its digits is 15876000, while the sum is 59.

The spelling of 1578139531457 in words is "one trillion, five hundred seventy-eight billion, one hundred thirty-nine million, five hundred thirty-one thousand, four hundred fifty-seven".