20231021977 has 2 divisors, whose sum is σ = 20231021978. Its totient is φ = 20231021976.

The previous prime is 20231021957. The next prime is 20231022013. The reversal of 20231021977 is 77912013202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20068688896 + 162333081 = 141664^2 + 12741^2 .

It is a cyclic number.

It is not a de Polignac number, because 20231021977 - 2⁷ = 20231021849 is a prime.

It is not a weakly prime, because it can be changed into another prime (20231021947) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10115510988 + 10115510989.

It is an arithmetic number, because the mean of its divisors is an integer number (10115510989).

Almost surely, 2^20231021977 is an apocalyptic number.

It is an amenable number.

20231021977 is a deficient number, since it is larger than the sum of its proper divisors (1).

20231021977 is an equidigital number, since it uses as much as digits as its factorization.

20231021977 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10584, while the sum is 34.

The spelling of 20231021977 in words is "twenty billion, two hundred thirty-one million, twenty-one thousand, nine hundred seventy-seven".