165378873561 has 32 divisors (see below), whose sum is σ = 265775136768. Its totient is φ = 90232285440.

The previous prime is 165378873551. The next prime is 165378873571.

It is a happy number.

165378873561 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (165378873551) and next prime (165378873571).

It is not a de Polignac number, because 165378873561 - 2¹⁰ = 165378872537 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 165378873495 and 165378873504.

It is not an unprimeable number, because it can be changed into a prime (165378873551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6395641 + ... + 6421446.

It is an arithmetic number, because the mean of its divisors is an integer number (8305473024).

Almost surely, 2^165378873561 is an apocalyptic number.

165378873561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

165378873561 is a deficient number, since it is larger than the sum of its proper divisors (100396263207).

165378873561 is a wasteful number, since it uses less digits than its factorization.

165378873561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12817141.

The product of its digits is 25401600, while the sum is 60.

The spelling of 165378873561 in words is "one hundred sixty-five billion, three hundred seventy-eight million, eight hundred seventy-three thousand, five hundred sixty-one".