51155600221 has 4 divisors (see below), whose sum is σ = 55806109344. Its totient is φ = 46505091100.

The previous prime is 51155600179. The next prime is 51155600227. The reversal of 51155600221 is 12200655115.

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 51155600221 - 2⁹ = 51155599709 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 51155600221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51155600227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2325254545 + ... + 2325254566.

It is an arithmetic number, because the mean of its divisors is an integer number (13951527336).

Almost surely, 2^51155600221 is an apocalyptic number.

It is an amenable number.

51155600221 is a deficient number, since it is larger than the sum of its proper divisors (4650509123).

51155600221 is a wasteful number, since it uses less digits than its factorization.

51155600221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4650509122.

The product of its (nonzero) digits is 3000, while the sum is 28.

The spelling of 51155600221 in words is "fifty-one billion, one hundred fifty-five million, six hundred thousand, two hundred twenty-one".