31857828987005 has 48 divisors (see below), whose sum is σ = 46738293356160. Its totient is φ = 20745241469568.

The previous prime is 31857828987001. The next prime is 31857828987041. The reversal of 31857828987005 is 50078982875813.

It is not a de Polignac number, because 31857828987005 - 2² = 31857828987001 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 31857828987005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31857828987001) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 19553294 + ... + 21119823.

It is an arithmetic number, because the mean of its divisors is an integer number (973714444920).

Almost surely, 2^{31857828987005} is an apocalyptic number.

31857828987005 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

31857828987005 is a deficient number, since it is larger than the sum of its proper divisors (14880464369155).

31857828987005 is a wasteful number, since it uses less digits than its factorization.

31857828987005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40673298 (or 40673291 counting only the distinct ones).

The product of its (nonzero) digits is 270950400, while the sum is 71.

Adding to 31857828987005 its sum of digits (71), we get a square (31857828987076 = 5644274²).

The spelling of 31857828987005 in words is "thirty-one trillion, eight hundred fifty-seven billion, eight hundred twenty-eight million, nine hundred eighty-seven thousand, five".