212905481 has 2 divisors, whose sum is σ = 212905482. Its totient is φ = 212905480.

The previous prime is 212905477. The next prime is 212905519. The reversal of 212905481 is 184509212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 185395456 + 27510025 = 13616^2 + 5245^2 .

It is a cyclic number.

It is not a de Polignac number, because 212905481 - 2² = 212905477 is a prime.

It is a super-2 number, since 2×212905481² = 90657487679682722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (212905471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106452740 + 106452741.

It is an arithmetic number, because the mean of its divisors is an integer number (106452741).

Almost surely, 2^212905481 is an apocalyptic number.

It is an amenable number.

212905481 is a deficient number, since it is larger than the sum of its proper divisors (1).

212905481 is an equidigital number, since it uses as much as digits as its factorization.

212905481 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5760, while the sum is 32.

The square root of 212905481 is about 14591.2809924283. The cubic root of 212905481 is about 597.1209114758.

The spelling of 212905481 in words is "two hundred twelve million, nine hundred five thousand, four hundred eighty-one".