20256603977 has 2 divisors, whose sum is σ = 20256603978. Its totient is φ = 20256603976.

The previous prime is 20256603967. The next prime is 20256604001. The reversal of 20256603977 is 77930665202.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12088782601 + 8167821376 = 109949^2 + 90376^2 .

It is a cyclic number.

It is not a de Polignac number, because 20256603977 - 2¹⁰ = 20256602953 is a prime.

It is not a weakly prime, because it can be changed into another prime (20256603937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10128301988 + 10128301989.

It is an arithmetic number, because the mean of its divisors is an integer number (10128301989).

Almost surely, 2^20256603977 is an apocalyptic number.

It is an amenable number.

20256603977 is a deficient number, since it is larger than the sum of its proper divisors (1).

20256603977 is an equidigital number, since it uses as much as digits as its factorization.

20256603977 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 952560, while the sum is 47.

The spelling of 20256603977 in words is "twenty billion, two hundred fifty-six million, six hundred three thousand, nine hundred seventy-seven".