28906387081 has 12 divisors (see below), whose sum is σ = 34217225476. Its totient is φ = 24257106720.

The previous prime is 28906387079. The next prime is 28906387099. The reversal of 28906387081 is 18078360982.

It can be written as a sum of positive squares in 2 ways, for example, as 6670805625 + 22235581456 = 81675^2 + 149116^2 .

It is not a de Polignac number, because 28906387081 - 2¹ = 28906387079 is a prime.

It is a super-2 number, since 2×28906387081² (a number of 22 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (52) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28906307081) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9186726 + ... + 9189871.

Almost surely, 2^28906387081 is an apocalyptic number.

It is an amenable number.

28906387081 is a deficient number, since it is larger than the sum of its proper divisors (5310838395).

28906387081 is a wasteful number, since it uses less digits than its factorization.

28906387081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18376632 (or 18376621 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 52.

The spelling of 28906387081 in words is "twenty-eight billion, nine hundred six million, three hundred eighty-seven thousand, eighty-one".