51017201620 has 144 divisors (see below), whose sum is σ = 143955548352. Its totient is φ = 14966031360.

The previous prime is 51017201617. The next prime is 51017201629. The reversal of 51017201620 is 2610271015.

It is a super-2 number, since 2×51017201620² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51017201629) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 44067 + ... + 322453.

It is an arithmetic number, because the mean of its divisors is an integer number (999691308).

Almost surely, 2^51017201620 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 51017201620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (71977774176).

51017201620 is an abundant number, since it is smaller than the sum of its proper divisors (92938346732).

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

51017201620 is a wasteful number, since it uses less digits than its factorization.

51017201620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 278438 (or 278429 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 25.

Adding to 51017201620 its reverse (2610271015), we get a palindrome (53627472635).

The spelling of 51017201620 in words is "fifty-one billion, seventeen million, two hundred one thousand, six hundred twenty".