212421457 has 2 divisors, whose sum is σ = 212421458. Its totient is φ = 212421456.

The previous prime is 212421449. The next prime is 212421481. The reversal of 212421457 is 754124212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 211964481 + 456976 = 14559^2 + 676^2 .

It is a cyclic number.

It is not a de Polignac number, because 212421457 - 2³ = 212421449 is a prime.

It is not a weakly prime, because it can be changed into another prime (212425457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106210728 + 106210729.

It is an arithmetic number, because the mean of its divisors is an integer number (106210729).

Almost surely, 2^212421457 is an apocalyptic number.

It is an amenable number.

212421457 is a deficient number, since it is larger than the sum of its proper divisors (1).

212421457 is an equidigital number, since it uses as much as digits as its factorization.

212421457 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4480, while the sum is 28.

The square root of 212421457 is about 14574.6854854573. The cubic root of 212421457 is about 596.6680655308.

Adding to 212421457 its reverse (754124212), we get a palindrome (966545669).

It can be divided in two parts, 212421 and 457, that added together give a triangular number (212878 = T₆₅₂).

The spelling of 212421457 in words is "two hundred twelve million, four hundred twenty-one thousand, four hundred fifty-seven".