215645040 has 120 divisors (see below), whose sum is σ = 779950080. Its totient is φ = 53079552.

The previous prime is 215644997. The next prime is 215645057. The reversal of 215645040 is 40546512.

215645040 is a `hidden beast` number, since 2 + 15 + 645 + 0 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

It is a zygodrome in base 6.

It is a junction number, because it is equal to n+sod(n) for n = 215644995 and 215645013.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2160 + ... + 20879.

It is an arithmetic number, because the mean of its divisors is an integer number (6499584).

Almost surely, 2^215645040 is an apocalyptic number.

215645040 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 215645040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (389975040).

215645040 is an abundant number, since it is smaller than the sum of its proper divisors (564305040).

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

215645040 is a wasteful number, since it uses less digits than its factorization.

215645040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23071 (or 23062 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The square root of 215645040 is about 14684.8575069696. The cubic root of 215645040 is about 599.6711531325.

The spelling of 215645040 in words is "two hundred fifteen million, six hundred forty-five thousand, forty".