210881664 has 256 divisors, whose sum is σ = 744192000. Its totient is φ = 57480192.

The previous prime is 210881659. The next prime is 210881681. The reversal of 210881664 is 466188012.

It is a super-2 number, since 2×210881664² = 88942152422817792, which contains 22 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 556227 + ... + 556605.

It is an arithmetic number, because the mean of its divisors is an integer number (2907000).

Almost surely, 2^210881664 is an apocalyptic number.

210881664 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 210881664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (372096000).

210881664 is an abundant number, since it is smaller than the sum of its proper divisors (533310336).

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

210881664 is a wasteful number, since it uses less digits than its factorization.

210881664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432 (or 414 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 210881664 is about 14521.7651819605. The cubic root of 210881664 is about 595.2228659270. Note that the first 3 decimals are identical.

The spelling of 210881664 in words is "two hundred ten million, eight hundred eighty-one thousand, six hundred sixty-four".