28653991 has 2 divisors, whose sum is σ = 28653992. Its totient is φ = 28653990.

The previous prime is 28653931. The next prime is 28653997. The reversal of 28653991 is 19935682.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28653991 - 2¹⁷ = 28522919 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28653997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14326995 + 14326996.

It is an arithmetic number, because the mean of its divisors is an integer number (14326996).

Almost surely, 2^28653991 is an apocalyptic number.

28653991 is a deficient number, since it is larger than the sum of its proper divisors (1).

28653991 is an equidigital number, since it uses as much as digits as its factorization.

28653991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 116640, while the sum is 43.

The square root of 28653991 is about 5352.9422750484. The cubic root of 28653991 is about 306.0048947627.

The spelling of 28653991 in words is "twenty-eight million, six hundred fifty-three thousand, nine hundred ninety-one".