1001561661104 has 20 divisors (see below), whose sum is σ = 1940654774520. Its totient is φ = 500747525760.

The previous prime is 1001561661101. The next prime is 1001561661131. The reversal of 1001561661104 is 4011661651001.

1001561661104 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (1001561661101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1832549 + ... + 2315460.

It is an arithmetic number, because the mean of its divisors is an integer number (97032738726).

Almost surely, 2^{1001561661104} is an apocalyptic number.

It is an amenable number.

1001561661104 is a deficient number, since it is larger than the sum of its proper divisors (939093113416).

1001561661104 is a wasteful number, since it uses less digits than its factorization.

1001561661104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4163108 (or 4163102 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 32.

The spelling of 1001561661104 in words is "one trillion, one billion, five hundred sixty-one million, six hundred sixty-one thousand, one hundred four".