20977799047 has 2 divisors, whose sum is σ = 20977799048. Its totient is φ = 20977799046.

The previous prime is 20977798999. The next prime is 20977799057. The reversal of 20977799047 is 74099777902.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20977799047 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20977799057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10488899523 + 10488899524.

It is an arithmetic number, because the mean of its divisors is an integer number (10488899524).

Almost surely, 2^20977799047 is an apocalyptic number.

20977799047 is a deficient number, since it is larger than the sum of its proper divisors (1).

20977799047 is an equidigital number, since it uses as much as digits as its factorization.

20977799047 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14002632, while the sum is 61.

The spelling of 20977799047 in words is "twenty billion, nine hundred seventy-seven million, seven hundred ninety-nine thousand, forty-seven".