28772091 has 10 divisors (see below), whose sum is σ = 42980652. Its totient is φ = 19181340.

The previous prime is 28772077. The next prime is 28772141. The reversal of 28772091 is 19027782.

It is not a de Polignac number, because 28772091 - 2¹⁴ = 28755707 is a prime.

It is not an unprimeable number, because it can be changed into a prime (24772091) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 177525 + ... + 177686.

Almost surely, 2^28772091 is an apocalyptic number.

28772091 is a deficient number, since it is larger than the sum of its proper divisors (14208561).

28772091 is an equidigital number, since it uses as much as digits as its factorization.

28772091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355223 (or 355214 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The square root of 28772091 is about 5363.9622481893. The cubic root of 28772091 is about 306.4247273922.

The spelling of 28772091 in words is "twenty-eight million, seven hundred seventy-two thousand, ninety-one".