128156281 has 4 divisors (see below), whose sum is σ = 139806864. Its totient is φ = 116505700.

The previous prime is 128156269. The next prime is 128156317. The reversal of 128156281 is 182651821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 182651821 = 11 ⋅16604711.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128156281 is a prime.

It is a super-2 number, since 2×128156281² = 32848064719501922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128156221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5825275 + ... + 5825296.

It is an arithmetic number, because the mean of its divisors is an integer number (34951716).

Almost surely, 2^128156281 is an apocalyptic number.

128156281 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

128156281 is a deficient number, since it is larger than the sum of its proper divisors (11650583).

128156281 is a wasteful number, since it uses less digits than its factorization.

128156281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11650582.

The product of its digits is 7680, while the sum is 34.

The square root of 128156281 is about 11320.6131017715. The cubic root of 128156281 is about 504.1734425001.

The spelling of 128156281 in words is "one hundred twenty-eight million, one hundred fifty-six thousand, two hundred eighty-one".