139651321 has 2 divisors, whose sum is σ = 139651322. Its totient is φ = 139651320.

The previous prime is 139651319. The next prime is 139651339. The reversal of 139651321 is 123156931.

It is a happy number.

139651321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 122345721 + 17305600 = 11061^2 + 4160^2 .

It is an emirp because it is prime and its reverse (123156931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 139651321 - 2¹ = 139651319 is a prime.

Together with 139651319, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (139661321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69825660 + 69825661.

It is an arithmetic number, because the mean of its divisors is an integer number (69825661).

Almost surely, 2^139651321 is an apocalyptic number.

It is an amenable number.

139651321 is a deficient number, since it is larger than the sum of its proper divisors (1).

139651321 is an equidigital number, since it uses as much as digits as its factorization.

139651321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4860, while the sum is 31.

The square root of 139651321 is about 11817.4160035094. The cubic root of 139651321 is about 518.8179771373.

The spelling of 139651321 in words is "one hundred thirty-nine million, six hundred fifty-one thousand, three hundred twenty-one".