65561116621 has 32 divisors (see below), whose sum is σ = 88047929088. Its totient is φ = 47145162240.

The previous prime is 65561116619. The next prime is 65561116739. The reversal of 65561116621 is 12661116556.

It is not a de Polignac number, because 65561116621 - 2¹ = 65561116619 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65561116601) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7520161 + ... + 7528873.

It is an arithmetic number, because the mean of its divisors is an integer number (2751497784).

Almost surely, 2^65561116621 is an apocalyptic number.

It is an amenable number.

65561116621 is a deficient number, since it is larger than the sum of its proper divisors (22486812467).

65561116621 is a wasteful number, since it uses less digits than its factorization.

65561116621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16261.

The product of its digits is 64800, while the sum is 40.

The spelling of 65561116621 in words is "sixty-five billion, five hundred sixty-one million, one hundred sixteen thousand, six hundred twenty-one".