77720023 has 2 divisors, whose sum is σ = 77720024. Its totient is φ = 77720022.

The previous prime is 77720021. The next prime is 77720099. The reversal of 77720023 is 32002777.

It is a weak prime.

It is an emirp because it is prime and its reverse (32002777) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77720023 - 2¹ = 77720021 is a prime.

Together with 77720021, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 77719973 and 77720000.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77720021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38860011 + 38860012.

It is an arithmetic number, because the mean of its divisors is an integer number (38860012).

Almost surely, 2^77720023 is an apocalyptic number.

77720023 is a deficient number, since it is larger than the sum of its proper divisors (1).

77720023 is an equidigital number, since it uses as much as digits as its factorization.

77720023 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4116, while the sum is 28.

The square root of 77720023 is about 8815.8960406756. The cubic root of 77720023 is about 426.7540389780.

The spelling of 77720023 in words is "seventy-seven million, seven hundred twenty thousand, twenty-three".