843294421721 has 2 divisors, whose sum is σ = 843294421722. Its totient is φ = 843294421720.

The previous prime is 843294421679. The next prime is 843294421729. The reversal of 843294421721 is 127124492348.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 651629959696 + 191664462025 = 807236^2 + 437795^2 .

It is a cyclic number.

It is not a de Polignac number, because 843294421721 - 2⁶ = 843294421657 is a prime.

It is a super-2 number, since 2×843294421721² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (843294421729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 421647210860 + 421647210861.

It is an arithmetic number, because the mean of its divisors is an integer number (421647210861).

Almost surely, 2^843294421721 is an apocalyptic number.

It is an amenable number.

843294421721 is a deficient number, since it is larger than the sum of its proper divisors (1).

843294421721 is an equidigital number, since it uses as much as digits as its factorization.

843294421721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 774144, while the sum is 47.

The spelling of 843294421721 in words is "eight hundred forty-three billion, two hundred ninety-four million, four hundred twenty-one thousand, seven hundred twenty-one".