51555450621 has 8 divisors (see below), whose sum is σ = 68944580224. Its totient is φ = 34268310720.

The previous prime is 51555450619. The next prime is 51555450641. The reversal of 51555450621 is 12605455515.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 51555450621 - 2¹ = 51555450619 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 51555450621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51555450601) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25496245 + ... + 25498266.

It is an arithmetic number, because the mean of its divisors is an integer number (8618072528).

Almost surely, 2^51555450621 is an apocalyptic number.

It is an amenable number.

51555450621 is a deficient number, since it is larger than the sum of its proper divisors (17389129603).

51555450621 is a wasteful number, since it uses less digits than its factorization.

51555450621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50994851.

The product of its (nonzero) digits is 150000, while the sum is 39.

The spelling of 51555450621 in words is "fifty-one billion, five hundred fifty-five million, four hundred fifty thousand, six hundred twenty-one".