366561561 has 4 divisors (see below), whose sum is σ = 488748752. Its totient is φ = 244374372.

The previous prime is 366561539. The next prime is 366561581. The reversal of 366561561 is 165165663.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 366561561 - 2¹¹ = 366559513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (366561581) 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, 61093591 + ... + 61093596.

It is an arithmetic number, because the mean of its divisors is an integer number (122187188).

Almost surely, 2^366561561 is an apocalyptic number.

It is an amenable number.

366561561 is a deficient number, since it is larger than the sum of its proper divisors (122187191).

366561561 is a wasteful number, since it uses less digits than its factorization.

366561561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122187190.

The product of its digits is 97200, while the sum is 39.

The square root of 366561561 is about 19145.7974762087. The cubic root of 366561561 is about 715.6746601211.

The spelling of 366561561 in words is "three hundred sixty-six million, five hundred sixty-one thousand, five hundred sixty-one".