2157906240 has 336 divisors, whose sum is σ = 8777508480. Its totient is φ = 476098560.

The previous prime is 2157906239. The next prime is 2157906259. The reversal of 2157906240 is 426097512.

2157906240 is a `hidden beast` number, since 21 + 5 + 7 + 9 + 0 + 624 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (336).

It is a super-3 number, since 3×2157906240³ (a number of 29 digits) contains 333 as substring.

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 = 2157906195 and 2157906204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 582795 + ... + 586485.

Almost surely, 2^2157906240 is an apocalyptic number.

2157906240 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 2157906240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4388754240).

2157906240 is an abundant number, since it is smaller than the sum of its proper divisors (6619602240).

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

2157906240 is a wasteful number, since it uses less digits than its factorization.

2157906240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3750 (or 3737 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 2157906240 is about 46453.2694220762. The cubic root of 2157906240 is about 1292.2430059197.

The spelling of 2157906240 in words is "two billion, one hundred fifty-seven million, nine hundred six thousand, two hundred forty".