651081984 has 144 divisors (see below), whose sum is σ = 1995205632. Its totient is φ = 184633344.

The previous prime is 651081979. The next prime is 651081989. The reversal of 651081984 is 489180156.

It is an interprime number because it is at equal distance from previous prime (651081979) and next prime (651081989).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (651081989) 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, 875917 + ... + 876659.

Almost surely, 2^651081984 is an apocalyptic number.

651081984 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 651081984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (997602816).

651081984 is an abundant number, since it is smaller than the sum of its proper divisors (1344123648).

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

651081984 is a wasteful number, since it uses less digits than its factorization.

651081984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 932 (or 918 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 42.

The square root of 651081984 is about 25516.3081969159. The cubic root of 651081984 is about 866.7194834347.

The spelling of 651081984 in words is "six hundred fifty-one million, eighty-one thousand, nine hundred eighty-four".