71897779 has 2 divisors, whose sum is σ = 71897780. Its totient is φ = 71897778.

The previous prime is 71897753. The next prime is 71897789. The reversal of 71897779 is 97779817.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 71897779 - 2¹¹ = 71895731 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (71897789) 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, 35948889 + 35948890.

It is an arithmetic number, because the mean of its divisors is an integer number (35948890).

Almost surely, 2^71897779 is an apocalyptic number.

71897779 is a deficient number, since it is larger than the sum of its proper divisors (1).

71897779 is an equidigital number, since it uses as much as digits as its factorization.

71897779 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1555848, while the sum is 55.

The square root of 71897779 is about 8479.2558046093. The cubic root of 71897779 is about 415.8197933574.

The spelling of 71897779 in words is "seventy-one million, eight hundred ninety-seven thousand, seven hundred seventy-nine".