211280081 has 4 divisors (see below), whose sum is σ = 212625972. Its totient is φ = 209934192.

The previous prime is 211280077. The next prime is 211280099. The reversal of 211280081 is 180082112.

It is a happy number.

211280081 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 76720081 + 134560000 = 8759^2 + 11600^2 .

It is a cyclic number.

It is not a de Polignac number, because 211280081 - 2² = 211280077 is a prime.

It is a super-2 number, since 2×211280081² = 89278545254733122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (211280021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 672710 + ... + 673023.

It is an arithmetic number, because the mean of its divisors is an integer number (53156493).

Almost surely, 2^211280081 is an apocalyptic number.

It is an amenable number.

211280081 is a deficient number, since it is larger than the sum of its proper divisors (1345891).

211280081 is a wasteful number, since it uses less digits than its factorization.

211280081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1345890.

The product of its (nonzero) digits is 256, while the sum is 23.

The square root of 211280081 is about 14535.4766347719. The cubic root of 211280081 is about 595.5974800021.

The spelling of 211280081 in words is "two hundred eleven million, two hundred eighty thousand, eighty-one".