51225042564 has 72 divisors (see below), whose sum is σ = 131012743680. Its totient is φ = 16873836672.

The previous prime is 51225042563. The next prime is 51225042577. The reversal of 51225042564 is 46524052215.

51225042564 is a `hidden beast` number, since 5 + 1 + 2 + 2 + 50 + 42 + 564 = 666.

It is a super-2 number, since 2×51225042564² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (51225042563) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8144629 + ... + 8150915.

It is an arithmetic number, because the mean of its divisors is an integer number (1819621440).

Almost surely, 2^51225042564 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51225042564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (65506371840).

51225042564 is an abundant number, since it is smaller than the sum of its proper divisors (79787701116).

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

51225042564 is a wasteful number, since it uses less digits than its factorization.

51225042564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8929 (or 8924 counting only the distinct ones).

The product of its (nonzero) digits is 96000, while the sum is 36.

Adding to 51225042564 its reverse (46524052215), we get a palindrome (97749094779).

The spelling of 51225042564 in words is "fifty-one billion, two hundred twenty-five million, forty-two thousand, five hundred sixty-four".