28911961 has 8 divisors (see below), whose sum is σ = 31207680. Its totient is φ = 26626512.

The previous prime is 28911941. The next prime is 28911973. The reversal of 28911961 is 16911982.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28911961 - 2⁷ = 28911833 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28911961.

It is not an unprimeable number, because it can be changed into a prime (28911941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3906 + ... + 8548.

It is an arithmetic number, because the mean of its divisors is an integer number (3900960).

Almost surely, 2^28911961 is an apocalyptic number.

It is an amenable number.

28911961 is a deficient number, since it is larger than the sum of its proper divisors (2295719).

28911961 is a wasteful number, since it uses less digits than its factorization.

28911961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5135.

The product of its digits is 7776, while the sum is 37.

The square root of 28911961 is about 5376.9843778832. The cubic root of 28911961 is about 306.9204666174.

It can be divided in two parts, 289119 and 61, that added together give a triangular number (289180 = T₇₆₀).

The spelling of 28911961 in words is "twenty-eight million, nine hundred eleven thousand, nine hundred sixty-one".