19782977 has 2 divisors, whose sum is σ = 19782978. Its totient is φ = 19782976.

The previous prime is 19782953. The next prime is 19782979. The reversal of 19782977 is 77928791.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18800896 + 982081 = 4336^2 + 991^2 .

It is a cyclic number.

It is not a de Polignac number, because 19782977 - 2⁶ = 19782913 is a prime.

Together with 19782979, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (19782979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9891488 + 9891489.

It is an arithmetic number, because the mean of its divisors is an integer number (9891489).

Almost surely, 2^19782977 is an apocalyptic number.

It is an amenable number.

19782977 is a deficient number, since it is larger than the sum of its proper divisors (1).

19782977 is an equidigital number, since it uses as much as digits as its factorization.

19782977 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 444528, while the sum is 50.

The square root of 19782977 is about 4447.8058635691. The cubic root of 19782977 is about 270.4563703844.

The spelling of 19782977 in words is "nineteen million, seven hundred eighty-two thousand, nine hundred seventy-seven".