213122881 has 4 divisors (see below), whose sum is σ = 213542100. Its totient is φ = 212703664.

The previous prime is 213122873. The next prime is 213122909. The reversal of 213122881 is 188221312.

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 201185856 + 11937025 = 14184^2 + 3455^2 .

It is a cyclic number.

It is not a de Polignac number, because 213122881 - 2³ = 213122873 is a prime.

It is a super-2 number, since 2×213122881² = 90842724811480322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213122821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 208846 + ... + 209863.

It is an arithmetic number, because the mean of its divisors is an integer number (53385525).

Almost surely, 2^213122881 is an apocalyptic number.

It is an amenable number.

213122881 is a deficient number, since it is larger than the sum of its proper divisors (419219).

213122881 is an equidigital number, since it uses as much as digits as its factorization.

213122881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 419218.

The product of its digits is 1536, while the sum is 28.

The square root of 213122881 is about 14598.7287460244. The cubic root of 213122881 is about 597.3240844609.

The spelling of 213122881 in words is "two hundred thirteen million, one hundred twenty-two thousand, eight hundred eighty-one".