28779791 has 2 divisors, whose sum is σ = 28779792. Its totient is φ = 28779790.

The previous prime is 28779781. The next prime is 28779823. The reversal of 28779791 is 19797782.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28779791 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28779731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14389895 + 14389896.

It is an arithmetic number, because the mean of its divisors is an integer number (14389896).

Almost surely, 2^28779791 is an apocalyptic number.

28779791 is a deficient number, since it is larger than the sum of its proper divisors (1).

28779791 is an equidigital number, since it uses as much as digits as its factorization.

28779791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 444528, while the sum is 50.

The square root of 28779791 is about 5364.6799531752. The cubic root of 28779791 is about 306.4520601287.

Subtracting from 28779791 its reverse (19797782), we obtain a square (8982009 = 2997²).

The spelling of 28779791 in words is "twenty-eight million, seven hundred seventy-nine thousand, seven hundred ninety-one".