28715052721 has 2 divisors, whose sum is σ = 28715052722. Its totient is φ = 28715052720.

The previous prime is 28715052703. The next prime is 28715052761. The reversal of 28715052721 is 12725051782.

It is a happy number.

It is an a-pointer prime, because the next prime (28715052761) can be obtained adding 28715052721 to its sum of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28714997025 + 55696 = 169455^2 + 236^2 .

It is a cyclic number.

It is not a de Polignac number, because 28715052721 - 2⁷ = 28715052593 is a prime.

It is not a weakly prime, because it can be changed into another prime (28715052701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14357526360 + 14357526361.

It is an arithmetic number, because the mean of its divisors is an integer number (14357526361).

Almost surely, 2^28715052721 is an apocalyptic number.

It is an amenable number.

28715052721 is a deficient number, since it is larger than the sum of its proper divisors (1).

28715052721 is an equidigital number, since it uses as much as digits as its factorization.

28715052721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 78400, while the sum is 40.

The spelling of 28715052721 in words is "twenty-eight billion, seven hundred fifteen million, fifty-two thousand, seven hundred twenty-one".