211648681 has 8 divisors (see below), whose sum is σ = 214801280. Its totient is φ = 208503072.

The previous prime is 211648669. The next prime is 211648693. The reversal of 211648681 is 186846112.

It is an interprime number because it is at equal distance from previous prime (211648669) and next prime (211648693).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 211648681 - 2⁹ = 211648169 is a prime.

It is a super-2 number, since 2×211648681² = 89590328338079522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 211648681.

It is not an unprimeable number, because it can be changed into a prime (211648651) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 111700 + ... + 113578.

It is an arithmetic number, because the mean of its divisors is an integer number (26850160).

Almost surely, 2^211648681 is an apocalyptic number.

It is an amenable number.

211648681 is a deficient number, since it is larger than the sum of its proper divisors (3152599).

211648681 is a wasteful number, since it uses less digits than its factorization.

211648681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3495.

The product of its digits is 18432, while the sum is 37.

The square root of 211648681 is about 14548.1504322715. The cubic root of 211648681 is about 595.9436392885.

The spelling of 211648681 in words is "two hundred eleven million, six hundred forty-eight thousand, six hundred eighty-one".