71978976449 has 2 divisors, whose sum is σ = 71978976450. Its totient is φ = 71978976448.

The previous prime is 71978976403. The next prime is 71978976479. The reversal of 71978976449 is 94467987917.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63181849600 + 8797126849 = 251360^2 + 93793^2 .

It is a cyclic number.

It is not a de Polignac number, because 71978976449 - 2³² = 67684009153 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 (71978976479) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35989488224 + 35989488225.

It is an arithmetic number, because the mean of its divisors is an integer number (35989488225).

Almost surely, 2^71978976449 is an apocalyptic number.

It is an amenable number.

71978976449 is a deficient number, since it is larger than the sum of its proper divisors (1).

71978976449 is an equidigital number, since it uses as much as digits as its factorization.

71978976449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 192036096, while the sum is 71.

The spelling of 71978976449 in words is "seventy-one billion, nine hundred seventy-eight million, nine hundred seventy-six thousand, four hundred forty-nine".