139523557 has 4 divisors (see below), whose sum is σ = 139631616. Its totient is φ = 139415500.

The previous prime is 139523551. The next prime is 139523561. The reversal of 139523557 is 755325931.

139523557 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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: 755325931 = 1861 ⋅405871.

It is a cyclic number.

It is not a de Polignac number, because 139523557 - 2¹¹ = 139521509 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 (139523551) 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, 52069 + ... + 54682.

It is an arithmetic number, because the mean of its divisors is an integer number (34907904).

Almost surely, 2^139523557 is an apocalyptic number.

It is an amenable number.

139523557 is a deficient number, since it is larger than the sum of its proper divisors (108059).

139523557 is a wasteful number, since it uses less digits than its factorization.

139523557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108058.

The product of its digits is 141750, while the sum is 40.

The square root of 139523557 is about 11812.0090162512. The cubic root of 139523557 is about 518.6597103805.

The spelling of 139523557 in words is "one hundred thirty-nine million, five hundred twenty-three thousand, five hundred fifty-seven".