28235351381 has 4 divisors (see below), whose sum is σ = 28236013164. Its totient is φ = 28234689600.

The previous prime is 28235351351. The next prime is 28235351399. The reversal of 28235351381 is 18315353282.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16112240356 + 12123111025 = 126934^2 + 110105^2 .

It is a cyclic number.

It is not a de Polignac number, because 28235351381 - 2⁶ = 28235351317 is a prime.

It is a super-2 number, since 2×28235351381² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28235351351) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 262130 + ... + 353811.

It is an arithmetic number, because the mean of its divisors is an integer number (7059003291).

Almost surely, 2^28235351381 is an apocalyptic number.

It is an amenable number.

28235351381 is a deficient number, since it is larger than the sum of its proper divisors (661783).

28235351381 is an equidigital number, since it uses as much as digits as its factorization.

28235351381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 661782.

The product of its digits is 172800, while the sum is 41.

The spelling of 28235351381 in words is "twenty-eight billion, two hundred thirty-five million, three hundred fifty-one thousand, three hundred eighty-one".