217904064 has 112 divisors (see below), whose sum is σ = 663049728. Its totient is φ = 61867008.

The previous prime is 217904059. The next prime is 217904077. The reversal of 217904064 is 460409712.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (112).

It is a super-2 number, since 2×217904064² = 94964362215432192, which contains 22 as substring.

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 264357 + ... + 265179.

Almost surely, 2^217904064 is an apocalyptic number.

217904064 is a gapful number since it is divisible by the number (24) 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 217904064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (331524864).

217904064 is an abundant number, since it is smaller than the sum of its proper divisors (445145664).

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

217904064 is a wasteful number, since it uses less digits than its factorization.

217904064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1042 (or 1032 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 33.

The square root of 217904064 is about 14761.5738998252. The cubic root of 217904064 is about 601.7578670318.

The spelling of 217904064 in words is "two hundred seventeen million, nine hundred four thousand, sixty-four".