61665405653 has 4 divisors (see below), whose sum is σ = 62710582080. Its totient is φ = 60620229228.

The previous prime is 61665405619. The next prime is 61665405679. The reversal of 61665405653 is 35650456616.

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 61665405653 - 2²⁸ = 61396970197 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 61665405598 and 61665405607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61665405953) 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, 522588125 + ... + 522588242.

It is an arithmetic number, because the mean of its divisors is an integer number (15677645520).

Almost surely, 2^61665405653 is an apocalyptic number.

It is an amenable number.

61665405653 is a deficient number, since it is larger than the sum of its proper divisors (1045176427).

61665405653 is a wasteful number, since it uses less digits than its factorization.

61665405653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1045176426.

The product of its (nonzero) digits is 1944000, while the sum is 47.

The spelling of 61665405653 in words is "sixty-one billion, six hundred sixty-five million, four hundred five thousand, six hundred fifty-three".