20004977 has 2 divisors, whose sum is σ = 20004978. Its totient is φ = 20004976.

The previous prime is 20004973. The next prime is 20004979. The reversal of 20004977 is 77940002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15335056 + 4669921 = 3916^2 + 2161^2 .

It is a cyclic number.

It is not a de Polignac number, because 20004977 - 2² = 20004973 is a prime.

Together with 20004979, 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 (20004973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10002488 + 10002489.

It is an arithmetic number, because the mean of its divisors is an integer number (10002489).

Almost surely, 2^20004977 is an apocalyptic number.

It is an amenable number.

20004977 is a deficient number, since it is larger than the sum of its proper divisors (1).

20004977 is an equidigital number, since it uses as much as digits as its factorization.

20004977 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3528, while the sum is 29.

The square root of 20004977 is about 4472.6923659022. The cubic root of 20004977 is about 271.4642758862.

Adding to 20004977 its reverse (77940002), we get a palindrome (97944979).

The spelling of 20004977 in words is "twenty million, four thousand, nine hundred seventy-seven".