28121701493 has 2 divisors, whose sum is σ = 28121701494. Its totient is φ = 28121701492.

The previous prime is 28121701483. The next prime is 28121701501. The reversal of 28121701493 is 39410712182.

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., 27319792369 + 801909124 = 165287^2 + 28318^2 .

It is a cyclic number.

It is not a de Polignac number, because 28121701493 - 2⁴ = 28121701477 is a prime.

It is a super-2 number, since 2×28121701493² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28121701463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14060850746 + 14060850747.

It is an arithmetic number, because the mean of its divisors is an integer number (14060850747).

Almost surely, 2^28121701493 is an apocalyptic number.

It is an amenable number.

28121701493 is a deficient number, since it is larger than the sum of its proper divisors (1).

28121701493 is an equidigital number, since it uses as much as digits as its factorization.

28121701493 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24192, while the sum is 38.

The spelling of 28121701493 in words is "twenty-eight billion, one hundred twenty-one million, seven hundred one thousand, four hundred ninety-three".