2157731660 has 144 divisors (see below), whose sum is σ = 5691591360. Its totient is φ = 683020800.

The previous prime is 2157731659. The next prime is 2157731669. The reversal of 2157731660 is 661377512.

It is not an unprimeable number, because it can be changed into a prime (2157731669) 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, 652010 + ... + 655310.

It is an arithmetic number, because the mean of its divisors is an integer number (39524940).

Almost surely, 2^2157731660 is an apocalyptic number.

2157731660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2157731660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2845795680).

2157731660 is an abundant number, since it is smaller than the sum of its proper divisors (3533859700).

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

2157731660 is a wasteful number, since it uses less digits than its factorization.

2157731660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3376 (or 3367 counting only the distinct ones).

The product of its (nonzero) digits is 52920, while the sum is 38.

The square root of 2157731660 is about 46451.3902913573. The cubic root of 2157731660 is about 1292.2081564185.

The spelling of 2157731660 in words is "two billion, one hundred fifty-seven million, seven hundred thirty-one thousand, six hundred sixty".