77920897 has 2 divisors, whose sum is σ = 77920898. Its totient is φ = 77920896.

The previous prime is 77920873. The next prime is 77920903. The reversal of 77920897 is 79802977.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 71166096 + 6754801 = 8436^2 + 2599^2 .

It is a cyclic number.

It is not a de Polignac number, because 77920897 - 2¹¹ = 77918849 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 77920897.

It is not a weakly prime, because it can be changed into another prime (77920837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38960448 + 38960449.

It is an arithmetic number, because the mean of its divisors is an integer number (38960449).

Almost surely, 2^77920897 is an apocalyptic number.

It is an amenable number.

77920897 is a deficient number, since it is larger than the sum of its proper divisors (1).

77920897 is an equidigital number, since it uses as much as digits as its factorization.

77920897 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 444528, while the sum is 49.

The square root of 77920897 is about 8827.2814048267. The cubic root of 77920897 is about 427.1213833675.

The spelling of 77920897 in words is "seventy-seven million, nine hundred twenty thousand, eight hundred ninety-seven".