61278439907 has 2 divisors, whose sum is σ = 61278439908. Its totient is φ = 61278439906.

The previous prime is 61278439883. The next prime is 61278439909. The reversal of 61278439907 is 70993487216.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61278439907 - 2⁶ = 61278439843 is a prime.

Together with 61278439909, 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 (61278439909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30639219953 + 30639219954.

It is an arithmetic number, because the mean of its divisors is an integer number (30639219954).

Almost surely, 2^61278439907 is an apocalyptic number.

61278439907 is a deficient number, since it is larger than the sum of its proper divisors (1).

61278439907 is an equidigital number, since it uses as much as digits as its factorization.

61278439907 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4572288, while the sum is 56.

The spelling of 61278439907 in words is "sixty-one billion, two hundred seventy-eight million, four hundred thirty-nine thousand, nine hundred seven".