138121007 has 2 divisors, whose sum is σ = 138121008. Its totient is φ = 138121006.

The previous prime is 138120991. The next prime is 138121069. The reversal of 138121007 is 700121831.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 138121007 - 2⁴ = 138120991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138121097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69060503 + 69060504.

It is an arithmetic number, because the mean of its divisors is an integer number (69060504).

Almost surely, 2^138121007 is an apocalyptic number.

138121007 is a deficient number, since it is larger than the sum of its proper divisors (1).

138121007 is an equidigital number, since it uses as much as digits as its factorization.

138121007 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 336, while the sum is 23.

The square root of 138121007 is about 11752.4893958684. The cubic root of 138121007 is about 516.9159250065.

Adding to 138121007 its reverse (700121831), we get a palindrome (838242838).

The spelling of 138121007 in words is "one hundred thirty-eight million, one hundred twenty-one thousand, seven".