653666536561 has 4 divisors (see below), whose sum is σ = 653669334000. Its totient is φ = 653663739124.

The previous prime is 653666536487. The next prime is 653666536573. The reversal of 653666536561 is 165635666356.

It is a happy number.

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 a cyclic number.

It is not a de Polignac number, because 653666536561 - 2¹⁹ = 653666012273 is a prime.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 653666536496 and 653666536505.

It is not an unprimeable number, because it can be changed into a prime (653666537561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1012711 + ... + 1527388.

It is an arithmetic number, because the mean of its divisors is an integer number (163417333500).

Almost surely, 2^653666536561 is an apocalyptic number.

It is an amenable number.

653666536561 is a deficient number, since it is larger than the sum of its proper divisors (2797439).

653666536561 is a wasteful number, since it uses less digits than its factorization.

653666536561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2797438.

The product of its digits is 52488000, while the sum is 58.

The spelling of 653666536561 in words is "six hundred fifty-three billion, six hundred sixty-six million, five hundred thirty-six thousand, five hundred sixty-one".