215525640 has 256 divisors, whose sum is σ = 763084800. Its totient is φ = 48153600.

The previous prime is 215525623. The next prime is 215525689. The reversal of 215525640 is 46525512.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 215525598 and 215525607.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 941046 + ... + 941274.

It is an arithmetic number, because the mean of its divisors is an integer number (2980800).

Almost surely, 2^215525640 is an apocalyptic number.

215525640 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 215525640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (381542400).

215525640 is an abundant number, since it is smaller than the sum of its proper divisors (547559160).

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

215525640 is a wasteful number, since it uses less digits than its factorization.

215525640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 308 (or 304 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 30.

The square root of 215525640 is about 14680.7915317942. The cubic root of 215525640 is about 599.5604558580.

The spelling of 215525640 in words is "two hundred fifteen million, five hundred twenty-five thousand, six hundred forty".