155921808708793 has 2 divisors, whose sum is σ = 155921808708794. Its totient is φ = 155921808708792.

The previous prime is 155921808708751. The next prime is 155921808708917. The reversal of 155921808708793 is 397807808129551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 93493273932864 + 62428534775929 = 9669192^2 + 7901173^2 .

It is an emirp because it is prime and its reverse (397807808129551) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-155921808708793 is a prime.

It is a super-2 number, since 2×155921808708793² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (155921808808793) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77960904354396 + 77960904354397.

It is an arithmetic number, because the mean of its divisors is an integer number (77960904354397).

Almost surely, 2^{155921808708793} is an apocalyptic number.

It is an amenable number.

155921808708793 is a deficient number, since it is larger than the sum of its proper divisors (1).

155921808708793 is an equidigital number, since it uses as much as digits as its factorization.

155921808708793 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 304819200, while the sum is 73.

The spelling of 155921808708793 in words is "one hundred fifty-five trillion, nine hundred twenty-one billion, eight hundred eight million, seven hundred eight thousand, seven hundred ninety-three".