1212400139 has 2 divisors, whose sum is σ = 1212400140. Its totient is φ = 1212400138.

The previous prime is 1212400099. The next prime is 1212400141. The reversal of 1212400139 is 9310042121.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1212400139 - 2⁸ = 1212399883 is a prime.

Together with 1212400141, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1212400199) 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, 606200069 + 606200070.

It is an arithmetic number, because the mean of its divisors is an integer number (606200070).

Almost surely, 2^1212400139 is an apocalyptic number.

1212400139 is a deficient number, since it is larger than the sum of its proper divisors (1).

1212400139 is an equidigital number, since it uses as much as digits as its factorization.

1212400139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 1212400139 is about 34819.5367430413. The cubic root of 1212400139 is about 1066.3063426286.

The spelling of 1212400139 in words is "one billion, two hundred twelve million, four hundred thousand, one hundred thirty-nine".