611500561561 has 4 divisors (see below), whose sum is σ = 611504016592. Its totient is φ = 611497106532.

The previous prime is 611500561519. The next prime is 611500561583. The reversal of 611500561561 is 165165005116.

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 611500561561 - 2³⁷ = 474061608089 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 611500561561.

It is not an unprimeable number, because it can be changed into a prime (611500561591) 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, 1446831 + ... + 1821076.

It is an arithmetic number, because the mean of its divisors is an integer number (152876004148).

Almost surely, 2^611500561561 is an apocalyptic number.

It is an amenable number.

611500561561 is a deficient number, since it is larger than the sum of its proper divisors (3455031).

611500561561 is a wasteful number, since it uses less digits than its factorization.

611500561561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3455030.

The product of its (nonzero) digits is 27000, while the sum is 37.

Adding to 611500561561 its reverse (165165005116), we get a palindrome (776665566677).

The spelling of 611500561561 in words is "six hundred eleven billion, five hundred million, five hundred sixty-one thousand, five hundred sixty-one".