68671562021 has 2 divisors, whose sum is σ = 68671562022. Its totient is φ = 68671562020.

The previous prime is 68671561979. The next prime is 68671562077. The reversal of 68671562021 is 12026517686.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39406617121 + 29264944900 = 198511^2 + 171070^2 .

It is a cyclic number.

It is not a de Polignac number, because 68671562021 - 2¹⁴ = 68671545637 is a prime.

It is a Sophie Germain 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 (61671562021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34335781010 + 34335781011.

It is an arithmetic number, because the mean of its divisors is an integer number (34335781011).

Almost surely, 2^68671562021 is an apocalyptic number.

It is an amenable number.

68671562021 is a deficient number, since it is larger than the sum of its proper divisors (1).

68671562021 is an equidigital number, since it uses as much as digits as its factorization.

68671562021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 241920, while the sum is 44.

The spelling of 68671562021 in words is "sixty-eight billion, six hundred seventy-one million, five hundred sixty-two thousand, twenty-one".