2231816781391 has 2 divisors, whose sum is σ = 2231816781392. Its totient is φ = 2231816781390.

The previous prime is 2231816781367. The next prime is 2231816781407. The reversal of 2231816781391 is 1931876181322.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2231816781391 - 2¹⁷ = 2231816650319 is a prime.

It is a super-3 number, since 3×2231816781391³ (a number of 38 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2231816781301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1115908390695 + 1115908390696.

It is an arithmetic number, because the mean of its divisors is an integer number (1115908390696).

Almost surely, 2^{2231816781391} is an apocalyptic number.

2231816781391 is a deficient number, since it is larger than the sum of its proper divisors (1).

2231816781391 is an equidigital number, since it uses as much as digits as its factorization.

2231816781391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 870912, while the sum is 52.

The spelling of 2231816781391 in words is "two trillion, two hundred thirty-one billion, eight hundred sixteen million, seven hundred eighty-one thousand, three hundred ninety-one".