20447231977 has 2 divisors, whose sum is σ = 20447231978. Its totient is φ = 20447231976.

The previous prime is 20447231969. The next prime is 20447232011. The reversal of 20447231977 is 77913274402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15972157161 + 4475074816 = 126381^2 + 66896^2 .

It is a cyclic number.

It is not a de Polignac number, because 20447231977 - 2³ = 20447231969 is a prime.

It is not a weakly prime, because it can be changed into another prime (20447231677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10223615988 + 10223615989.

It is an arithmetic number, because the mean of its divisors is an integer number (10223615989).

Almost surely, 2^20447231977 is an apocalyptic number.

It is an amenable number.

20447231977 is a deficient number, since it is larger than the sum of its proper divisors (1).

20447231977 is an equidigital number, since it uses as much as digits as its factorization.

20447231977 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 592704, while the sum is 46.

The spelling of 20447231977 in words is "twenty billion, four hundred forty-seven million, two hundred thirty-one thousand, nine hundred seventy-seven".