77919973 has 2 divisors, whose sum is σ = 77919974. Its totient is φ = 77919972.

The previous prime is 77919971. The next prime is 77920033. The reversal of 77919973 is 37991977.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67272804 + 10647169 = 8202^2 + 3263^2 .

It is an emirp because it is prime and its reverse (37991977) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77919973 - 2¹ = 77919971 is a prime.

Together with 77919971, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 77919973.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77919971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38959986 + 38959987.

It is an arithmetic number, because the mean of its divisors is an integer number (38959987).

Almost surely, 2^77919973 is an apocalyptic number.

It is an amenable number.

77919973 is a deficient number, since it is larger than the sum of its proper divisors (1).

77919973 is an equidigital number, since it uses as much as digits as its factorization.

77919973 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 750141, while the sum is 52.

The square root of 77919973 is about 8827.2290669269. The cubic root of 77919973 is about 427.1196950668.

The spelling of 77919973 in words is "seventy-seven million, nine hundred nineteen thousand, nine hundred seventy-three".