138185501561 has 8 divisors (see below), whose sum is σ = 139424325600. Its totient is φ = 136950173280.

The previous prime is 138185501557. The next prime is 138185501611. The reversal of 138185501561 is 165105581831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 138185501561 - 2² = 138185501557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138185500561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 794495 + ... + 952676.

It is an arithmetic number, because the mean of its divisors is an integer number (17428040700).

Almost surely, 2^138185501561 is an apocalyptic number.

It is an amenable number.

138185501561 is a deficient number, since it is larger than the sum of its proper divisors (1238824039).

138185501561 is a wasteful number, since it uses less digits than its factorization.

138185501561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1747879.

The product of its (nonzero) digits is 144000, while the sum is 44.

The spelling of 138185501561 in words is "one hundred thirty-eight billion, one hundred eighty-five million, five hundred one thousand, five hundred sixty-one".