10212578398721 has 2 divisors, whose sum is σ = 10212578398722. Its totient is φ = 10212578398720.

The previous prime is 10212578398709. The next prime is 10212578398739. The reversal of 10212578398721 is 12789387521201.

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., 6266936458225 + 3945641940496 = 2503385^2 + 1986364^2 .

It is an emirp because it is prime and its reverse (12789387521201) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 10212578398721 - 2⁶ = 10212578398657 is a prime.

It is not a weakly prime, because it can be changed into another prime (10212578368721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5106289199360 + 5106289199361.

It is an arithmetic number, because the mean of its divisors is an integer number (5106289199361).

Almost surely, 2^{10212578398721} is an apocalyptic number.

It is an amenable number.

10212578398721 is a deficient number, since it is larger than the sum of its proper divisors (1).

10212578398721 is an equidigital number, since it uses as much as digits as its factorization.

10212578398721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3386880, while the sum is 56.

The spelling of 10212578398721 in words is "ten trillion, two hundred twelve billion, five hundred seventy-eight million, three hundred ninety-eight thousand, seven hundred twenty-one".