28780771 has 2 divisors, whose sum is σ = 28780772. Its totient is φ = 28780770.

The previous prime is 28780757. The next prime is 28780777. The reversal of 28780771 is 17708782.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28780771 is a prime.

It is not a weakly prime, because it can be changed into another prime (28780777) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14390385 + 14390386.

It is an arithmetic number, because the mean of its divisors is an integer number (14390386).

Almost surely, 2^28780771 is an apocalyptic number.

28780771 is a deficient number, since it is larger than the sum of its proper divisors (1).

28780771 is an equidigital number, since it uses as much as digits as its factorization.

28780771 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 43904, while the sum is 40.

The square root of 28780771 is about 5364.7712905584. The cubic root of 28780771 is about 306.4555384909.

The spelling of 28780771 in words is "twenty-eight million, seven hundred eighty thousand, seven hundred seventy-one".