20128113877 has 2 divisors, whose sum is σ = 20128113878. Its totient is φ = 20128113876.

The previous prime is 20128113871. The next prime is 20128113881. The reversal of 20128113877 is 77831182102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17369658436 + 2758455441 = 131794^2 + 52521^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20128113877 is a prime.

It is a super-2 number, since 2×20128113877² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20128113871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10064056938 + 10064056939.

It is an arithmetic number, because the mean of its divisors is an integer number (10064056939).

Almost surely, 2^20128113877 is an apocalyptic number.

It is an amenable number.

20128113877 is a deficient number, since it is larger than the sum of its proper divisors (1).

20128113877 is an equidigital number, since it uses as much as digits as its factorization.

20128113877 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 37632, while the sum is 40.

Adding to 20128113877 its reverse (77831182102), we get a palindrome (97959295979).

The spelling of 20128113877 in words is "twenty billion, one hundred twenty-eight million, one hundred thirteen thousand, eight hundred seventy-seven".