2123845231781 has 24 divisors (see below), whose sum is σ = 2628493205184. Its totient is φ = 1680297989760.

The previous prime is 2123845231763. The next prime is 2123845231789. The reversal of 2123845231781 is 1871325483212.

It is not a de Polignac number, because 2123845231781 - 2¹⁸ = 2123844969637 is a prime.

It is a super-2 number, since 2×2123845231781² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2123845231789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22177241 + ... + 22272801.

It is an arithmetic number, because the mean of its divisors is an integer number (109520550216).

Almost surely, 2^{2123845231781} is an apocalyptic number.

It is an amenable number.

2123845231781 is a deficient number, since it is larger than the sum of its proper divisors (504647973403).

2123845231781 is a wasteful number, since it uses less digits than its factorization.

2123845231781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114381 (or 114368 counting only the distinct ones).

The product of its digits is 645120, while the sum is 47.

The spelling of 2123845231781 in words is "two trillion, one hundred twenty-three billion, eight hundred forty-five million, two hundred thirty-one thousand, seven hundred eighty-one".