51620164240 has 80 divisors (see below), whose sum is σ = 121530792960. Its totient is φ = 20389207040.

The previous prime is 51620164171. The next prime is 51620164247. The reversal of 51620164240 is 4246102615.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-3 number, since 3×51620164240³ (a number of 33 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (51620164247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2081031 + ... + 2105689.

It is an arithmetic number, because the mean of its divisors is an integer number (1519134912).

Almost surely, 2^51620164240 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 51620164240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (60765396480).

51620164240 is an abundant number, since it is smaller than the sum of its proper divisors (69910628720).

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

51620164240 is a wasteful number, since it uses less digits than its factorization.

51620164240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25000 (or 24994 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 31.

Adding to 51620164240 its reverse (4246102615), we get a palindrome (55866266855).

The spelling of 51620164240 in words is "fifty-one billion, six hundred twenty million, one hundred sixty-four thousand, two hundred forty".