4066021561 has 16 divisors (see below), whose sum is σ = 4677304320. Its totient is φ = 3462394320.

The previous prime is 4066021523. The next prime is 4066021571. The reversal of 4066021561 is 1651206604.

4066021561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 4066021561 - 2²⁵ = 4032467129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (4066021571) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1387680 + ... + 1390606.

It is an arithmetic number, because the mean of its divisors is an integer number (292331520).

Almost surely, 2^4066021561 is an apocalyptic number.

It is an amenable number.

4066021561 is a deficient number, since it is larger than the sum of its proper divisors (611282759).

4066021561 is a wasteful number, since it uses less digits than its factorization.

4066021561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4164.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 4066021561 is about 63765.3633330823. The cubic root of 4066021561 is about 1596.0869954704.

The spelling of 4066021561 in words is "four billion, sixty-six million, twenty-one thousand, five hundred sixty-one".