28779091 has 8 divisors (see below), whose sum is σ = 33048000. Its totient is φ = 24785640.

The previous prime is 28779073. The next prime is 28779097. The reversal of 28779091 is 19097782.

It is a happy number.

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

It is not a de Polignac number, because 28779091 - 2⁵ = 28779059 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28779097) 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, 68641 + ... + 69058.

It is an arithmetic number, because the mean of its divisors is an integer number (4131000).

Almost surely, 2^28779091 is an apocalyptic number.

28779091 is a deficient number, since it is larger than the sum of its proper divisors (4268909).

28779091 is a wasteful number, since it uses less digits than its factorization.

28779091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137729.

The product of its (nonzero) digits is 63504, while the sum is 43.

The square root of 28779091 is about 5364.6147112351. The cubic root of 28779091 is about 306.4495755360.

The spelling of 28779091 in words is "twenty-eight million, seven hundred seventy-nine thousand, ninety-one".