1066561641 has 8 divisors (see below), whose sum is σ = 1580091360. Its totient is φ = 711041076.

The previous prime is 1066561607. The next prime is 1066561663. The reversal of 1066561641 is 1461656601.

It is a happy number.

1066561641 is a `hidden beast` number, since 1 + 0 + 6 + 6 + 5 + 6 + 1 + 641 = 666.

It is not a de Polignac number, because 1066561641 - 2¹⁹ = 1066037353 is a prime.

It is a super-2 number, since 2×1066561641² = 2275107468105225762, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1066561596 and 1066561605.

It is not an unprimeable number, because it can be changed into a prime (1066562641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19751115 + ... + 19751168.

It is an arithmetic number, because the mean of its divisors is an integer number (197511420).

Almost surely, 2^1066561641 is an apocalyptic number.

It is an amenable number.

1066561641 is a deficient number, since it is larger than the sum of its proper divisors (513529719).

1066561641 is an equidigital number, since it uses as much as digits as its factorization.

1066561641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39502292 (or 39502286 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 1066561641 is about 32658.2553269460. The cubic root of 1066561641 is about 1021.7123745245.

The spelling of 1066561641 in words is "one billion, sixty-six million, five hundred sixty-one thousand, six hundred forty-one".