1577139109561 has 4 divisors (see below), whose sum is σ = 1602993849124. Its totient is φ = 1551284370000.

The previous prime is 1577139109541. The next prime is 1577139109607. The reversal of 1577139109561 is 1659019317751.

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 90339319225 + 1486799790336 = 300565^2 + 1219344^2 .

It is a cyclic number.

It is not a de Polignac number, because 1577139109561 - 2¹⁹ = 1577138585273 is a prime.

It is a super-2 number, since 2×1577139109561² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1577139109541) 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, 12927369690 + ... + 12927369811.

It is an arithmetic number, because the mean of its divisors is an integer number (400748462281).

Almost surely, 2^{1577139109561} is an apocalyptic number.

It is an amenable number.

1577139109561 is a deficient number, since it is larger than the sum of its proper divisors (25854739563).

1577139109561 is an equidigital number, since it uses as much as digits as its factorization.

1577139109561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25854739562.

The product of its (nonzero) digits is 1786050, while the sum is 55.

The spelling of 1577139109561 in words is "one trillion, five hundred seventy-seven billion, one hundred thirty-nine million, one hundred nine thousand, five hundred sixty-one".