655501661561 has 16 divisors (see below), whose sum is σ = 677204575488. Its totient is φ = 634143120000.

The previous prime is 655501661537. The next prime is 655501661567. The reversal of 655501661561 is 165166105556.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-655501661561 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (47).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (655501661567) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2738066 + ... + 2967828.

It is an arithmetic number, because the mean of its divisors is an integer number (42325285968).

Almost surely, 2^655501661561 is an apocalyptic number.

It is an amenable number.

655501661561 is a deficient number, since it is larger than the sum of its proper divisors (21702913927).

655501661561 is a wasteful number, since it uses less digits than its factorization.

655501661561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230512.

The product of its (nonzero) digits is 810000, while the sum is 47.

The spelling of 655501661561 in words is "six hundred fifty-five billion, five hundred one million, six hundred sixty-one thousand, five hundred sixty-one".