139661399 has 2 divisors, whose sum is σ = 139661400. Its totient is φ = 139661398.

The previous prime is 139661387. The next prime is 139661407. The reversal of 139661399 is 993166931.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 139661399 - 2⁴ = 139661383 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (139661309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69830699 + 69830700.

It is an arithmetic number, because the mean of its divisors is an integer number (69830700).

Almost surely, 2^139661399 is an apocalyptic number.

139661399 is a deficient number, since it is larger than the sum of its proper divisors (1).

139661399 is an equidigital number, since it uses as much as digits as its factorization.

139661399 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 236196, while the sum is 47.

The square root of 139661399 is about 11817.8424003707. The cubic root of 139661399 is about 518.8304570808.

The spelling of 139661399 in words is "one hundred thirty-nine million, six hundred sixty-one thousand, three hundred ninety-nine".