20055997477 has 2 divisors, whose sum is σ = 20055997478. Its totient is φ = 20055997476.

The previous prime is 20055997463. The next prime is 20055997483. The reversal of 20055997477 is 77479955002.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16166105316 + 3889892161 = 127146^2 + 62369^2 .

It is a cyclic number.

It is not a de Polignac number, because 20055997477 - 2²³ = 20047608869 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20055997457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10027998738 + 10027998739.

It is an arithmetic number, because the mean of its divisors is an integer number (10027998739).

Almost surely, 2^20055997477 is an apocalyptic number.

It is an amenable number.

20055997477 is a deficient number, since it is larger than the sum of its proper divisors (1).

20055997477 is an equidigital number, since it uses as much as digits as its factorization.

20055997477 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5556600, while the sum is 55.

The spelling of 20055997477 in words is "twenty billion, fifty-five million, nine hundred ninety-seven thousand, four hundred seventy-seven".