139528491 has 4 divisors (see below), whose sum is σ = 186037992. Its totient is φ = 93018992.

The previous prime is 139528463. The next prime is 139528513. The reversal of 139528491 is 194825931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 194825931 = 3 ⋅64941977.

It is a cyclic number.

It is not a de Polignac number, because 139528491 - 2¹⁰ = 139527467 is a prime.

It is not an unprimeable number, because it can be changed into a prime (139528091) 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, 23254746 + ... + 23254751.

It is an arithmetic number, because the mean of its divisors is an integer number (46509498).

Almost surely, 2^139528491 is an apocalyptic number.

139528491 is a deficient number, since it is larger than the sum of its proper divisors (46509501).

139528491 is an equidigital number, since it uses as much as digits as its factorization.

139528491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46509500.

The product of its digits is 77760, while the sum is 42.

The square root of 139528491 is about 11812.2178696467. The cubic root of 139528491 is about 518.6658241315.

The spelling of 139528491 in words is "one hundred thirty-nine million, five hundred twenty-eight thousand, four hundred ninety-one".