128891616 has 48 divisors (see below), whose sum is σ = 386676864. Its totient is φ = 36825984.

The previous prime is 128891599. The next prime is 128891617. The reversal of 128891616 is 616198821.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-2 number, since 2×128891616² = 33226097350182912, which contains 22 as substring.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128891617) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 95230 + ... + 96573.

It is an arithmetic number, because the mean of its divisors is an integer number (8055768).

Almost surely, 2^128891616 is an apocalyptic number.

128891616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

128891616 is an abundant number, since it is smaller than the sum of its proper divisors (257785248).

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

128891616 is a wasteful number, since it uses less digits than its factorization.

128891616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191823 (or 191815 counting only the distinct ones).

The product of its digits is 41472, while the sum is 42.

The square root of 128891616 is about 11353.0443494245. The cubic root of 128891616 is about 505.1358860543.

The spelling of 128891616 in words is "one hundred twenty-eight million, eight hundred ninety-one thousand, six hundred sixteen".