51555721603 has 4 divisors (see below), whose sum is σ = 51557816440. Its totient is φ = 51553626768.

The previous prime is 51555721601. The next prime is 51555721631. The reversal of 51555721603 is 30612755515.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 51555721603 - 2¹ = 51555721601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51555721601) 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, 1010058 + ... + 1059871.

It is an arithmetic number, because the mean of its divisors is an integer number (12889454110).

Almost surely, 2^51555721603 is an apocalyptic number.

51555721603 is a deficient number, since it is larger than the sum of its proper divisors (2094837).

51555721603 is a wasteful number, since it uses less digits than its factorization.

51555721603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2094836.

The product of its (nonzero) digits is 157500, while the sum is 40.

The spelling of 51555721603 in words is "fifty-one billion, five hundred fifty-five million, seven hundred twenty-one thousand, six hundred three".