28028352460721 has 2 divisors, whose sum is σ = 28028352460722. Its totient is φ = 28028352460720.

The previous prime is 28028352460613. The next prime is 28028352460769. The reversal of 28028352460721 is 12706425382082.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18978700167025 + 9049652293696 = 4356455^2 + 3008264^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28028352460721 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28028352460721.

It is not a weakly prime, because it can be changed into another prime (28028352460021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14014176230360 + 14014176230361.

It is an arithmetic number, because the mean of its divisors is an integer number (14014176230361).

Almost surely, 2^{28028352460721} is an apocalyptic number.

It is an amenable number.

28028352460721 is a deficient number, since it is larger than the sum of its proper divisors (1).

28028352460721 is an equidigital number, since it uses as much as digits as its factorization.

28028352460721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2580480, while the sum is 50.

The spelling of 28028352460721 in words is "twenty-eight trillion, twenty-eight billion, three hundred fifty-two million, four hundred sixty thousand, seven hundred twenty-one".