651361986 has 144 divisors (see below), whose sum is σ = 1659359520. Its totient is φ = 189889920.

The previous prime is 651361981. The next prime is 651362003. The reversal of 651361986 is 689163156.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (651361981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 7318630 + ... + 7318718.

It is an arithmetic number, because the mean of its divisors is an integer number (11523330).

Almost surely, 2^651361986 is an apocalyptic number.

651361986 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 651361986, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (829679760).

651361986 is an abundant number, since it is smaller than the sum of its proper divisors (1007997534).

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

651361986 is a wasteful number, since it uses less digits than its factorization.

651361986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191 (or 142 counting only the distinct ones).

The product of its digits is 233280, while the sum is 45.

The square root of 651361986 is about 25521.7943334711. The cubic root of 651361986 is about 866.8437117264.

The spelling of 651361986 in words is "six hundred fifty-one million, three hundred sixty-one thousand, nine hundred eighty-six".