217620648 has 128 divisors (see below), whose sum is σ = 695884800. Its totient is φ = 61725888.

The previous prime is 217620647. The next prime is 217620653. The reversal of 217620648 is 846026712.

217620648 is a `hidden beast` number, since 2 + 1 + 7 + 6 + 2 + 0 + 648 = 666.

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

It is a nialpdrome in base 6.

It is a zygodrome in base 6.

It is not an unprimeable number, because it can be changed into a prime (217620647) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 246015 + ... + 246897.

It is an arithmetic number, because the mean of its divisors is an integer number (5436600).

Almost surely, 2^217620648 is an apocalyptic number.

217620648 is a gapful number since it is divisible by the number (28) 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 217620648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (347942400).

217620648 is an abundant number, since it is smaller than the sum of its proper divisors (478264152).

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

217620648 is a wasteful number, since it uses less digits than its factorization.

217620648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1068 (or 1058 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 217620648 is about 14751.9709869563. The cubic root of 217620648 is about 601.4968625653.

The spelling of 217620648 in words is "two hundred seventeen million, six hundred twenty thousand, six hundred forty-eight".