128261916 has 18 divisors (see below), whose sum is σ = 324217712. Its totient is φ = 42753960.

The previous prime is 128261897. The next prime is 128261921. The reversal of 128261916 is 619162821.

128261916 is a `hidden beast` number, since 1 + 28 + 2 + 619 + 16 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×128261916² = 32902238191982112, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 3562831 = 128261916 / (1 + 2 + 8 + 2 + 6 + 1 + 9 + 1 + 6).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1781380 + ... + 1781451.

Almost surely, 2^128261916 is an apocalyptic number.

It is an amenable number.

128261916 is an abundant number, since it is smaller than the sum of its proper divisors (195955796).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

128261916 is a wasteful number, since it uses less digits than its factorization.

128261916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3562841 (or 3562836 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 128261916 is about 11325.2777449385. The cubic root of 128261916 is about 504.3119289763.

The spelling of 128261916 in words is "one hundred twenty-eight million, two hundred sixty-one thousand, nine hundred sixteen".