128911157761 has 2 divisors, whose sum is σ = 128911157762. Its totient is φ = 128911157760.

The previous prime is 128911157747. The next prime is 128911157807. The reversal of 128911157761 is 167751119821.

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., 107423995536 + 21487162225 = 327756^2 + 146585^2 .

It is a cyclic number.

It is not a de Polignac number, because 128911157761 - 2⁵ = 128911157729 is a prime.

It is not a weakly prime, because it can be changed into another prime (128911157261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64455578880 + 64455578881.

It is an arithmetic number, because the mean of its divisors is an integer number (64455578881).

Almost surely, 2^128911157761 is an apocalyptic number.

It is an amenable number.

128911157761 is a deficient number, since it is larger than the sum of its proper divisors (1).

128911157761 is an equidigital number, since it uses as much as digits as its factorization.

128911157761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 211680, while the sum is 49.

The spelling of 128911157761 in words is "one hundred twenty-eight billion, nine hundred eleven million, one hundred fifty-seven thousand, seven hundred sixty-one".