71278913 has 2 divisors, whose sum is σ = 71278914. Its totient is φ = 71278912.

The previous prime is 71278871. The next prime is 71278939. The reversal of 71278913 is 31987217.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 46348864 + 24930049 = 6808^2 + 4993^2 .

It is a cyclic number.

It is not a de Polignac number, because 71278913 - 2⁶ = 71278849 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (71278013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35639456 + 35639457.

It is an arithmetic number, because the mean of its divisors is an integer number (35639457).

Almost surely, 2^71278913 is an apocalyptic number.

It is an amenable number.

71278913 is a deficient number, since it is larger than the sum of its proper divisors (1).

71278913 is an equidigital number, since it uses as much as digits as its factorization.

71278913 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21168, while the sum is 38.

The square root of 71278913 is about 8442.6839926649. The cubic root of 71278913 is about 414.6232861497.

The spelling of 71278913 in words is "seventy-one million, two hundred seventy-eight thousand, nine hundred thirteen".