51209564904 has 128 divisors (see below), whose sum is σ = 145626096000. Its totient is φ = 16668633600.

The previous prime is 51209564891. The next prime is 51209564927. The reversal of 51209564904 is 40946590215.

51209564904 is a `hidden beast` number, since 51 + 20 + 95 + 6 + 490 + 4 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 51209564904.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1817484 + ... + 1845444.

It is an arithmetic number, because the mean of its divisors is an integer number (1137703875).

Almost surely, 2^51209564904 is an apocalyptic number.

51209564904 is a gapful number since it is divisible by the number (54) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51209564904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72813048000).

51209564904 is an abundant number, since it is smaller than the sum of its proper divisors (94416531096).

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

51209564904 is a wasteful number, since it uses less digits than its factorization.

51209564904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28176 (or 28166 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 45.

The spelling of 51209564904 in words is "fifty-one billion, two hundred nine million, five hundred sixty-four thousand, nine hundred four".