139071521 has 8 divisors (see below), whose sum is σ = 143145600. Its totient is φ = 135055440.

The previous prime is 139071481. The next prime is 139071533. The reversal of 139071521 is 125170931.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-139071521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139071721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9611 + ... + 19248.

It is an arithmetic number, because the mean of its divisors is an integer number (17893200).

Almost surely, 2^139071521 is an apocalyptic number.

It is an amenable number.

139071521 is a deficient number, since it is larger than the sum of its proper divisors (4074079).

139071521 is an equidigital number, since it uses as much as digits as its factorization.

139071521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28999.

The product of its (nonzero) digits is 1890, while the sum is 29.

The square root of 139071521 is about 11792.8588985029. The cubic root of 139071521 is about 518.0989770766.

The spelling of 139071521 in words is "one hundred thirty-nine million, seventy-one thousand, five hundred twenty-one".