212487721 has 2 divisors, whose sum is σ = 212487722. Its totient is φ = 212487720.

The previous prime is 212487713. The next prime is 212487787. The reversal of 212487721 is 127784212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 194212096 + 18275625 = 13936^2 + 4275^2 .

It is a cyclic number.

It is not a de Polignac number, because 212487721 - 2³ = 212487713 is a prime.

It is not a weakly prime, because it can be changed into another prime (212484721) 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, 106243860 + 106243861.

It is an arithmetic number, because the mean of its divisors is an integer number (106243861).

Almost surely, 2^212487721 is an apocalyptic number.

It is an amenable number.

212487721 is a deficient number, since it is larger than the sum of its proper divisors (1).

212487721 is an equidigital number, since it uses as much as digits as its factorization.

212487721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12544, while the sum is 34.

The square root of 212487721 is about 14576.9585648036. The cubic root of 212487721 is about 596.7301017971.

The spelling of 212487721 in words is "two hundred twelve million, four hundred eighty-seven thousand, seven hundred twenty-one".