4131985021 has 2 divisors, whose sum is σ = 4131985022. Its totient is φ = 4131985020.

The previous prime is 4131984973. The next prime is 4131985049. The reversal of 4131985021 is 1205891314.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3895132921 + 236852100 = 62411^2 + 15390^2 .

It is a cyclic number.

It is not a de Polignac number, because 4131985021 - 2²⁹ = 3595114109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4131985051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2065992510 + 2065992511.

It is an arithmetic number, because the mean of its divisors is an integer number (2065992511).

Almost surely, 2^4131985021 is an apocalyptic number.

It is an amenable number.

4131985021 is a deficient number, since it is larger than the sum of its proper divisors (1).

4131985021 is an equidigital number, since it uses as much as digits as its factorization.

4131985021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 34.

The square root of 4131985021 is about 64280.5182073076. The cubic root of 4131985021 is about 1604.6718947067.

The spelling of 4131985021 in words is "four billion, one hundred thirty-one million, nine hundred eighty-five thousand, twenty-one".