651021016520 has 128 divisors (see below), whose sum is σ = 1714565318400. Its totient is φ = 217815284736.

The previous prime is 651021016511. The next prime is 651021016523. The reversal of 651021016520 is 25610120156.

It is a happy number.

651021016520 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×651021016520² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (651021016523) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13327982 + ... + 13376738.

It is an arithmetic number, because the mean of its divisors is an integer number (13395041550).

Almost surely, 2^651021016520 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 651021016520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (857282659200).

651021016520 is an abundant number, since it is smaller than the sum of its proper divisors (1063544301880).

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

651021016520 is a wasteful number, since it uses less digits than its factorization.

651021016520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49927 (or 49923 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 29.

Adding to 651021016520 its reverse (25610120156), we get a palindrome (676631136676).

The spelling of 651021016520 in words is "six hundred fifty-one billion, twenty-one million, sixteen thousand, five hundred twenty".