28931696641 has 2 divisors, whose sum is σ = 28931696642. Its totient is φ = 28931696640.

The previous prime is 28931696609. The next prime is 28931696669. The reversal of 28931696641 is 14669613982.

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., 25184420416 + 3747276225 = 158696^2 + 61215^2 .

It is a cyclic number.

It is not a de Polignac number, because 28931696641 - 2⁵ = 28931696609 is a prime.

It is not a weakly prime, because it can be changed into another prime (28931696671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14465848320 + 14465848321.

It is an arithmetic number, because the mean of its divisors is an integer number (14465848321).

Almost surely, 2^28931696641 is an apocalyptic number.

It is an amenable number.

28931696641 is a deficient number, since it is larger than the sum of its proper divisors (1).

28931696641 is an equidigital number, since it uses as much as digits as its factorization.

28931696641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3359232, while the sum is 55.

The spelling of 28931696641 in words is "twenty-eight billion, nine hundred thirty-one million, six hundred ninety-six thousand, six hundred forty-one".