28236112721 has 2 divisors, whose sum is σ = 28236112722. Its totient is φ = 28236112720.

The previous prime is 28236112717. The next prime is 28236112783. The reversal of 28236112721 is 12721163282.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14927952400 + 13308160321 = 122180^2 + 115361^2 .

It is a cyclic number.

It is not a de Polignac number, because 28236112721 - 2² = 28236112717 is a prime.

It is not a weakly prime, because it can be changed into another prime (28236114721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14118056360 + 14118056361.

It is an arithmetic number, because the mean of its divisors is an integer number (14118056361).

Almost surely, 2^28236112721 is an apocalyptic number.

It is an amenable number.

28236112721 is a deficient number, since it is larger than the sum of its proper divisors (1).

28236112721 is an equidigital number, since it uses as much as digits as its factorization.

28236112721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16128, while the sum is 35.

The spelling of 28236112721 in words is "twenty-eight billion, two hundred thirty-six million, one hundred twelve thousand, seven hundred twenty-one".