51516620221 has 8 divisors (see below), whose sum is σ = 56577132000. Its totient is φ = 46518972240.

The previous prime is 51516620179. The next prime is 51516620227. The reversal of 51516620221 is 12202661515.

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

It is a cyclic number.

It is not a de Polignac number, because 51516620221 - 2¹⁹ = 51516095933 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51516620227) 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, 15714231 + ... + 15717508.

It is an arithmetic number, because the mean of its divisors is an integer number (7072141500).

Almost surely, 2^51516620221 is an apocalyptic number.

It is an amenable number.

51516620221 is a deficient number, since it is larger than the sum of its proper divisors (5060511779).

51516620221 is a wasteful number, since it uses less digits than its factorization.

51516620221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31431899.

The product of its (nonzero) digits is 7200, while the sum is 31.

The spelling of 51516620221 in words is "fifty-one billion, five hundred sixteen million, six hundred twenty thousand, two hundred twenty-one".