651530312020 has 72 divisors (see below), whose sum is σ = 1630414978920. Its totient is φ = 217933470720.

The previous prime is 651530311997. The next prime is 651530312047. The reversal of 651530312020 is 20213035156.

It can be written as a sum of positive squares in 4 ways, for example, as 5172198724 + 646358113296 = 71918^2 + 803964^2 .

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a self number, because there is not a number n which added to its sum of digits gives 651530312020.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8067465 + ... + 8147824.

It is an arithmetic number, because the mean of its divisors is an integer number (22644652485).

Almost surely, 2^651530312020 is an apocalyptic number.

It is an amenable number.

651530312020 is an abundant number, since it is smaller than the sum of its proper divisors (978884666900).

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

651530312020 is a wasteful number, since it uses less digits than its factorization.

651530312020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16215353 (or 16215344 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 28.

Adding to 651530312020 its reverse (20213035156), we get a palindrome (671743347176).

The spelling of 651530312020 in words is "six hundred fifty-one billion, five hundred thirty million, three hundred twelve thousand, twenty".