138057861 has 4 divisors (see below), whose sum is σ = 184077152. Its totient is φ = 92038572.

The previous prime is 138057853. The next prime is 138057883. The reversal of 138057861 is 168750831.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 168750831 = 3 ⋅56250277.

It is not a de Polignac number, because 138057861 - 2³ = 138057853 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138057811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23009641 + ... + 23009646.

It is an arithmetic number, because the mean of its divisors is an integer number (46019288).

Almost surely, 2^138057861 is an apocalyptic number.

It is an amenable number.

138057861 is a deficient number, since it is larger than the sum of its proper divisors (46019291).

138057861 is an equidigital number, since it uses as much as digits as its factorization.

138057861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46019290.

The product of its (nonzero) digits is 40320, while the sum is 39.

The square root of 138057861 is about 11749.8025940864. The cubic root of 138057861 is about 516.8371386600.

The spelling of 138057861 in words is "one hundred thirty-eight million, fifty-seven thousand, eight hundred sixty-one".