2138787321831 has 28 divisors (see below), whose sum is σ = 3208439199000. Its totient is φ = 1425091132080.

The previous prime is 2138787321761. The next prime is 2138787321841. The reversal of 2138787321831 is 1381237878312.

2138787321831 is a `hidden beast` number, since 2 + 1 + 387 + 87 + 3 + 2 + 183 + 1 = 666.

It is not a de Polignac number, because 2138787321831 - 2¹³ = 2138787313639 is a prime.

It is a super-2 number, since 2×2138787321831² (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 (2138787321841) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 568420 + ... + 2144918.

It is an arithmetic number, because the mean of its divisors is an integer number (114587114250).

Almost surely, 2^{2138787321831} is an apocalyptic number.

2138787321831 is a deficient number, since it is larger than the sum of its proper divisors (1069651877169).

2138787321831 is an equidigital number, since it uses as much as digits as its factorization.

2138787321831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1578378 (or 1578363 counting only the distinct ones).

The product of its digits is 2709504, while the sum is 54.

The spelling of 2138787321831 in words is "two trillion, one hundred thirty-eight billion, seven hundred eighty-seven million, three hundred twenty-one thousand, eight hundred thirty-one".