1243068821 has 2 divisors, whose sum is σ = 1243068822. Its totient is φ = 1243068820.

The previous prime is 1243068793. The next prime is 1243068877. The reversal of 1243068821 is 1288603421.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1088340100 + 154728721 = 32990^2 + 12439^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1243068821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1243068121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621534410 + 621534411.

It is an arithmetic number, because the mean of its divisors is an integer number (621534411).

Almost surely, 2^1243068821 is an apocalyptic number.

It is an amenable number.

1243068821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243068821 is an equidigital number, since it uses as much as digits as its factorization.

1243068821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18432, while the sum is 35.

The square root of 1243068821 is about 35257.1811266868. The cubic root of 1243068821 is about 1075.2226172455. Note that the first 3 decimals are identical.

The spelling of 1243068821 in words is "one billion, two hundred forty-three million, sixty-eight thousand, eight hundred twenty-one".