1615138516161 has 15 divisors (see below), whose sum is σ = 2412754869811. Its totient is φ = 1076751385488.

The previous prime is 1615138516111. The next prime is 1615138516219. The reversal of 1615138516161 is 1616158315161.

The square root of 1615138516161 is 1270881.

It is a perfect power (a square), and thus also a powerful number.

1615138516161 is a `hidden beast` number, since 1 + 6 + 1 + 51 + 385 + 161 + 61 = 666.

It can be written as a sum of positive squares in only one way, i.e., 327549037761 + 1287589478400 = 572319^2 + 1134720^2 .

It is not a de Polignac number, because 1615138516161 - 2¹⁵ = 1615138483393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1615138516111) by changing a digit.

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 14 ways as a sum of consecutive naturals, for example, 11367325 + ... + 11508533.

Almost surely, 2^{1615138516161} is an apocalyptic number.

1615138516161 is the 1270881-st square number.

1615138516161 is the 635441-st centered octagonal number.

It is an amenable number.

1615138516161 is a deficient number, since it is larger than the sum of its proper divisors (797616353650).

1615138516161 is an frugal number, since it uses more digits than its factorization.

1615138516161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 282430 (or 141212 counting only the distinct ones).

The product of its digits is 129600, while the sum is 45.

The spelling of 1615138516161 in words is "one trillion, six hundred fifteen billion, one hundred thirty-eight million, five hundred sixteen thousand, one hundred sixty-one".