51661712220 has 48 divisors (see below), whose sum is σ = 144841028640. Its totient is φ = 13758529536.

The previous prime is 51661712213. The next prime is 51661712231. The reversal of 51661712220 is 2221716615.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 513697 + ... + 605976.

It is an arithmetic number, because the mean of its divisors is an integer number (3017521430).

Almost surely, 2^51661712220 is an apocalyptic number.

It is an amenable number.

51661712220 is an abundant number, since it is smaller than the sum of its proper divisors (93179316420).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51661712220 is a wasteful number, since it uses less digits than its factorization.

51661712220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1120454 (or 1120452 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 33.

The spelling of 51661712220 in words is "fifty-one billion, six hundred sixty-one million, seven hundred twelve thousand, two hundred twenty".