3843541721 has 2 divisors, whose sum is σ = 3843541722. Its totient is φ = 3843541720.

The previous prime is 3843541693. The next prime is 3843541729. The reversal of 3843541721 is 1271453483.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1970383321 + 1873158400 = 44389^2 + 43280^2 .

It is a cyclic number.

It is not a de Polignac number, because 3843541721 - 2³⁰ = 2769799897 is a prime.

It is a super-2 number, since 2×3843541721² = 29545625922135283682, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (3843541729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1921770860 + 1921770861.

It is an arithmetic number, because the mean of its divisors is an integer number (1921770861).

Almost surely, 2^3843541721 is an apocalyptic number.

It is an amenable number.

3843541721 is a deficient number, since it is larger than the sum of its proper divisors (1).

3843541721 is an equidigital number, since it uses as much as digits as its factorization.

3843541721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 80640, while the sum is 38.

The square root of 3843541721 is about 61996.3040914537. The cubic root of 3843541721 is about 1566.4283449514.

The spelling of 3843541721 in words is "three billion, eight hundred forty-three million, five hundred forty-one thousand, seven hundred twenty-one".