28235729891 has 2 divisors, whose sum is σ = 28235729892. Its totient is φ = 28235729890.

The previous prime is 28235729813. The next prime is 28235730059. The reversal of 28235729891 is 19892753282.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28235729891 - 2¹⁴ = 28235713507 is a prime.

It is a super-3 number, since 3×28235729891³ (a number of 32 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (28235729491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14117864945 + 14117864946.

It is an arithmetic number, because the mean of its divisors is an integer number (14117864946).

Almost surely, 2^28235729891 is an apocalyptic number.

28235729891 is a deficient number, since it is larger than the sum of its proper divisors (1).

28235729891 is an equidigital number, since it uses as much as digits as its factorization.

28235729891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4354560, while the sum is 56.

The spelling of 28235729891 in words is "twenty-eight billion, two hundred thirty-five million, seven hundred twenty-nine thousand, eight hundred ninety-one".