651689820 has 192 divisors, whose sum is σ = 2136637440. Its totient is φ = 164583936.

The previous prime is 651689807. The next prime is 651689821. The reversal of 651689820 is 28986156.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (651689821) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1701349 + ... + 1701731.

It is an arithmetic number, because the mean of its divisors is an integer number (11128320).

Almost surely, 2^651689820 is an apocalyptic number.

651689820 is a gapful number since it is divisible by the number (60) 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 651689820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1068318720).

651689820 is an abundant number, since it is smaller than the sum of its proper divisors (1484947620).

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

651689820 is a wasteful number, since it uses less digits than its factorization.

651689820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 561 (or 553 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 45.

The square root of 651689820 is about 25528.2161538953. The cubic root of 651689820 is about 866.9891163730.

The spelling of 651689820 in words is "six hundred fifty-one million, six hundred eighty-nine thousand, eight hundred twenty".