128877565 has 4 divisors (see below), whose sum is σ = 154653084. Its totient is φ = 103102048.

The previous prime is 128877557. The next prime is 128877583. The reversal of 128877565 is 565778821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 565778821 = 43 ⋅13157647.

It can be written as a sum of positive squares in 2 ways, for example, as 79512889 + 49364676 = 8917^2 + 7026^2 .

It is a cyclic number.

It is not a de Polignac number, because 128877565 - 2³ = 128877557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12887752 + ... + 12887761.

It is an arithmetic number, because the mean of its divisors is an integer number (38663271).

Almost surely, 2^128877565 is an apocalyptic number.

It is an amenable number.

128877565 is a deficient number, since it is larger than the sum of its proper divisors (25775519).

128877565 is an equidigital number, since it uses as much as digits as its factorization.

128877565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25775518.

The product of its digits is 940800, while the sum is 49.

The square root of 128877565 is about 11352.4255117574. The cubic root of 128877565 is about 505.1175297472.

The spelling of 128877565 in words is "one hundred twenty-eight million, eight hundred seventy-seven thousand, five hundred sixty-five".