561541166365401 has 24 divisors (see below), whose sum is σ = 826436643369480. Its totient is φ = 367289558528256.

The previous prime is 561541166365379. The next prime is 561541166365409. The reversal of 561541166365401 is 104563661145165.

561541166365401 is a `hidden beast` number, since 5 + 6 + 1 + 5 + 4 + 1 + 1 + 66 + 36 + 540 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 3205618099776 + 558335548265625 = 1790424^2 + 23629125^2 .

It is not a de Polignac number, because 561541166365401 - 2²³ = 561541157976793 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (561541166365409) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9991035 + ... + 34970031.

It is an arithmetic number, because the mean of its divisors is an integer number (34434860140395).

Almost surely, 2^{561541166365401} is an apocalyptic number.

It is an amenable number.

561541166365401 is a deficient number, since it is larger than the sum of its proper divisors (264895477004079).

561541166365401 is a wasteful number, since it uses less digits than its factorization.

561541166365401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25026185 (or 25026182 counting only the distinct ones).

The product of its (nonzero) digits is 7776000, while the sum is 54.

The spelling of 561541166365401 in words is "five hundred sixty-one trillion, five hundred forty-one billion, one hundred sixty-six million, three hundred sixty-five thousand, four hundred one".