61506055553 has 4 divisors (see below), whose sum is σ = 61668341040. Its totient is φ = 61343770068.

The previous prime is 61506055549. The next prime is 61506055627. The reversal of 61506055553 is 35555060516.

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 61506055553 - 2² = 61506055549 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 61506055553.

It is not an unprimeable number, because it can be changed into a prime (61506355553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81142175 + ... + 81142932.

It is an arithmetic number, because the mean of its divisors is an integer number (15417085260).

Almost surely, 2^61506055553 is an apocalyptic number.

It is an amenable number.

61506055553 is a deficient number, since it is larger than the sum of its proper divisors (162285487).

61506055553 is a wasteful number, since it uses less digits than its factorization.

61506055553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162285486.

The product of its (nonzero) digits is 337500, while the sum is 41.

The spelling of 61506055553 in words is "sixty-one billion, five hundred six million, fifty-five thousand, five hundred fifty-three".