20211131977 has 2 divisors, whose sum is σ = 20211131978. Its totient is φ = 20211131976.

The previous prime is 20211131971. The next prime is 20211132037. The reversal of 20211131977 is 77913111202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14797262736 + 5413869241 = 121644^2 + 73579^2 .

It is a cyclic number.

It is not a de Polignac number, because 20211131977 - 2¹⁹ = 20210607689 is a prime.

It is not a weakly prime, because it can be changed into another prime (20211131971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105565988 + 10105565989.

It is an arithmetic number, because the mean of its divisors is an integer number (10105565989).

Almost surely, 2^20211131977 is an apocalyptic number.

It is an amenable number.

20211131977 is a deficient number, since it is larger than the sum of its proper divisors (1).

20211131977 is an equidigital number, since it uses as much as digits as its factorization.

20211131977 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5292, while the sum is 34.

The spelling of 20211131977 in words is "twenty billion, two hundred eleven million, one hundred thirty-one thousand, nine hundred seventy-seven".