51209879616 has 315 divisors, whose sum is σ = 176980309869. Its totient is φ = 14598807552.

The previous prime is 51209879597. The next prime is 51209879621. The reversal of 51209879616 is 61697890215.

The square root of 51209879616 is 226296.

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

51209879616 is a `hidden beast` number, since 5 + 12 + 0 + 9 + 8 + 7 + 9 + 616 = 666.

It can be written as a sum of positive squares in only one way, i.e., 31295025216 + 19914854400 = 176904^2 + 141120^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 114052960 + ... + 114053408.

Almost surely, 2^51209879616 is an apocalyptic number.

51209879616 is a gapful number since it is divisible by the number (56) formed by its first and last digit.

51209879616 is the 226296-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51209879616

51209879616 is an abundant number, since it is smaller than the sum of its proper divisors (125770430253).

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

51209879616 is an frugal number, since it uses more digits than its factorization.

51209879616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 936 (or 461 counting only the distinct ones).

The product of its (nonzero) digits is 1632960, while the sum is 54.

It can be divided in two parts, 5120 and 9879616, that added together give a square (9884736 = 3144²).

The spelling of 51209879616 in words is "fifty-one billion, two hundred nine million, eight hundred seventy-nine thousand, six hundred sixteen".