138787679 has 2 divisors, whose sum is σ = 138787680. Its totient is φ = 138787678.

The previous prime is 138787669. The next prime is 138787687. The reversal of 138787679 is 976787831.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 138787679 - 2⁸ = 138787423 is a prime.

It is a Sophie Germain 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 (138787669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69393839 + 69393840.

It is an arithmetic number, because the mean of its divisors is an integer number (69393840).

Almost surely, 2^138787679 is an apocalyptic number.

138787679 is a deficient number, since it is larger than the sum of its proper divisors (1).

138787679 is an equidigital number, since it uses as much as digits as its factorization.

138787679 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3556224, while the sum is 56.

The square root of 138787679 is about 11780.8182652989. The cubic root of 138787679 is about 517.7462606950.

The spelling of 138787679 in words is "one hundred thirty-eight million, seven hundred eighty-seven thousand, six hundred seventy-nine".