781221011201123 has 2 divisors, whose sum is σ = 781221011201124. Its totient is φ = 781221011201122.

The previous prime is 781221011201089. The next prime is 781221011201129. The reversal of 781221011201123 is 321102110122187.

It is a strong prime.

It is an emirp because it is prime and its reverse (321102110122187) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 781221011201123 - 2¹² = 781221011197027 is a prime.

It is a super-5 number, since 5×781221011201123⁵ (a number of 76 digits) contains 55555 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 781221011201123.

It is not a weakly prime, because it can be changed into another prime (781221011201129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 390610505600561 + 390610505600562.

It is an arithmetic number, because the mean of its divisors is an integer number (390610505600562).

Almost surely, 2^{781221011201123} is an apocalyptic number.

781221011201123 is a deficient number, since it is larger than the sum of its proper divisors (1).

781221011201123 is an equidigital number, since it uses as much as digits as its factorization.

781221011201123 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2688, while the sum is 32.

The spelling of 781221011201123 in words is "seven hundred eighty-one trillion, two hundred twenty-one billion, eleven million, two hundred one thousand, one hundred twenty-three".