661001841 has 6 divisors (see below), whose sum is σ = 954780450. Its totient is φ = 440667888.

The previous prime is 661001827. The next prime is 661001903. The reversal of 661001841 is 148100166.

661001841 is a `hidden beast` number, since 6 + 610 + 0 + 1 + 8 + 41 = 666.

661001841 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 650250000 + 10751841 = 25500^2 + 3279^2 .

It is not a de Polignac number, because 661001841 - 2¹³ = 660993649 is a prime.

It is not an unprimeable number, because it can be changed into a prime (661001801) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 36722316 + ... + 36722333.

It is an arithmetic number, because the mean of its divisors is an integer number (159130075).

Almost surely, 2^661001841 is an apocalyptic number.

It is an amenable number.

661001841 is a deficient number, since it is larger than the sum of its proper divisors (293778609).

661001841 is a wasteful number, since it uses less digits than its factorization.

661001841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73444655 (or 73444652 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 661001841 is about 25709.9560676404. The cubic root of 661001841 is about 871.0990825903.

The spelling of 661001841 in words is "six hundred sixty-one million, one thousand, eight hundred forty-one".