51221647684 has 9 divisors (see below), whose sum is σ = 89638675581. Its totient is φ = 25610597520.

The previous prime is 51221647669. The next prime is 51221647733. The reversal of 51221647684 is 48674612215.

The square root of 51221647684 is 226322.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 44910934084 + 6310713600 = 211922^2 + 79440^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 396064 + ... + 509224.

Almost surely, 2^51221647684 is an apocalyptic number.

51221647684 is the 226322-nd square number.

It is an amenable number.

51221647684 is a deficient number, since it is larger than the sum of its proper divisors (38417027897).

51221647684 is an frugal number, since it uses more digits than its factorization.

51221647684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226326 (or 113163 counting only the distinct ones).

The product of its digits is 645120, while the sum is 46.

The spelling of 51221647684 in words is "fifty-one billion, two hundred twenty-one million, six hundred forty-seven thousand, six hundred eighty-four".