212454821 has 2 divisors, whose sum is σ = 212454822. Its totient is φ = 212454820.

The previous prime is 212454817. The next prime is 212454833. The reversal of 212454821 is 128454212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 148230625 + 64224196 = 12175^2 + 8014^2 .

It is a cyclic number.

It is not a de Polignac number, because 212454821 - 2² = 212454817 is a prime.

It is a super-2 number, since 2×212454821² = 90274101932284082, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212454881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106227410 + 106227411.

It is an arithmetic number, because the mean of its divisors is an integer number (106227411).

Almost surely, 2^212454821 is an apocalyptic number.

It is an amenable number.

212454821 is a deficient number, since it is larger than the sum of its proper divisors (1).

212454821 is an equidigital number, since it uses as much as digits as its factorization.

212454821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5120, while the sum is 29.

The square root of 212454821 is about 14575.8300278235. The cubic root of 212454821 is about 596.6993024744.

The spelling of 212454821 in words is "two hundred twelve million, four hundred fifty-four thousand, eight hundred twenty-one".