231257071818 has 80 divisors (see below), whose sum is σ = 526903720200. Its totient is φ = 75790080000.

The previous prime is 231257071817. The next prime is 231257071841. The reversal of 231257071818 is 818170752132.

231257071818 is a `hidden beast` number, since 2 + 3 + 1 + 2 + 570 + 71 + 8 + 1 + 8 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 53445579489 + 177811492329 = 231183^2 + 421677^2 .

It is a super-3 number, since 3×231257071818³ (a number of 35 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (231257071817) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 39534958 + ... + 39540806.

Almost surely, 2^231257071818 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 231257071818, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (263451860100).

231257071818 is an abundant number, since it is smaller than the sum of its proper divisors (295646648382).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

231257071818 is a wasteful number, since it uses less digits than its factorization.

231257071818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9925 (or 9916 counting only the distinct ones).

The product of its (nonzero) digits is 188160, while the sum is 45.

The spelling of 231257071818 in words is "two hundred thirty-one billion, two hundred fifty-seven million, seventy-one thousand, eight hundred eighteen".