2157384240 has 640 divisors, whose sum is σ = 8742297600. Its totient is φ = 483840000.

The previous prime is 2157384227. The next prime is 2157384253. The reversal of 2157384240 is 424837512.

It is a happy number.

2157384240 is a `hidden beast` number, since 2 + 1 + 573 + 8 + 42 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (2157384227) and next prime (2157384253).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 2157384195 and 2157384204.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 21360190 + ... + 21360290.

It is an arithmetic number, because the mean of its divisors is an integer number (13659840).

Almost surely, 2^2157384240 is an apocalyptic number.

2157384240 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 2157384240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4371148800).

2157384240 is an abundant number, since it is smaller than the sum of its proper divisors (6584913360).

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

2157384240 is a wasteful number, since it uses less digits than its factorization.

2157384240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194 (or 182 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 36.

The square root of 2157384240 is about 46447.6505326157. The cubic root of 2157384240 is about 1292.1387991605.

The spelling of 2157384240 in words is "two billion, one hundred fifty-seven million, three hundred eighty-four thousand, two hundred forty".