215514640 has 80 divisors (see below), whose sum is σ = 561481920. Its totient is φ = 76239360.

The previous prime is 215514613. The next prime is 215514641. The reversal of 215514640 is 46415512.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 215514599 and 215514608.

It is not an unprimeable number, because it can be changed into a prime (215514641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29251 + ... + 35869.

It is an arithmetic number, because the mean of its divisors is an integer number (7018524).

Almost surely, 2^215514640 is an apocalyptic number.

215514640 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 215514640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (280740960).

215514640 is an abundant number, since it is smaller than the sum of its proper divisors (345967280).

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

215514640 is a wasteful number, since it uses less digits than its factorization.

215514640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6680 (or 6674 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 215514640 is about 14680.4168878135. The cubic root of 215514640 is about 599.5502555601.

The spelling of 215514640 in words is "two hundred fifteen million, five hundred fourteen thousand, six hundred forty".