8429733721 has 2 divisors, whose sum is σ = 8429733722. Its totient is φ = 8429733720.

The previous prime is 8429733709. The next prime is 8429733727. The reversal of 8429733721 is 1273379248.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6125253696 + 2304480025 = 78264^2 + 48005^2 .

It is a cyclic number.

It is not a de Polignac number, because 8429733721 - 2¹⁵ = 8429700953 is a prime.

It is not a weakly prime, because it can be changed into another prime (8429733727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4214866860 + 4214866861.

It is an arithmetic number, because the mean of its divisors is an integer number (4214866861).

Almost surely, 2^8429733721 is an apocalyptic number.

It is an amenable number.

8429733721 is a deficient number, since it is larger than the sum of its proper divisors (1).

8429733721 is an equidigital number, since it uses as much as digits as its factorization.

8429733721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 508032, while the sum is 46.

The square root of 8429733721 is about 91813.5813537409. The cubic root of 8429733721 is about 2035.1884007186.

The spelling of 8429733721 in words is "eight billion, four hundred twenty-nine million, seven hundred thirty-three thousand, seven hundred twenty-one".