139305421 has 2 divisors, whose sum is σ = 139305422. Its totient is φ = 139305420.

The previous prime is 139305409. The next prime is 139305427. The reversal of 139305421 is 124503931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 138980521 + 324900 = 11789^2 + 570^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-139305421 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 139305421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (139305427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69652710 + 69652711.

It is an arithmetic number, because the mean of its divisors is an integer number (69652711).

Almost surely, 2^139305421 is an apocalyptic number.

It is an amenable number.

139305421 is a deficient number, since it is larger than the sum of its proper divisors (1).

139305421 is an equidigital number, since it uses as much as digits as its factorization.

139305421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 139305421 is about 11802.7717507372. The cubic root of 139305421 is about 518.3892724947.

The spelling of 139305421 in words is "one hundred thirty-nine million, three hundred five thousand, four hundred twenty-one".