993321157865497 has 2 divisors, whose sum is σ = 993321157865498. Its totient is φ = 993321157865496.

The previous prime is 993321157865441. The next prime is 993321157865501. The reversal of 993321157865497 is 794568751123399.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 991397100358681 + 1924057506816 = 31486459^2 + 1387104^2 .

It is a cyclic number.

It is not a de Polignac number, because 993321157865497 - 2²³ = 993321149476889 is a prime.

It is a super-2 number, since 2×993321157865497² (a number of 31 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (993321157805497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 496660578932748 + 496660578932749.

It is an arithmetic number, because the mean of its divisors is an integer number (496660578932749).

Almost surely, 2^{993321157865497} is an apocalyptic number.

It is an amenable number.

993321157865497 is a deficient number, since it is larger than the sum of its proper divisors (1).

993321157865497 is an equidigital number, since it uses as much as digits as its factorization.

993321157865497 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3086294400, while the sum is 79.

The spelling of 993321157865497 in words is "nine hundred ninety-three trillion, three hundred twenty-one billion, one hundred fifty-seven million, eight hundred sixty-five thousand, four hundred ninety-seven".