651920 has 40 divisors (see below), whose sum is σ = 1573560. Its totient is φ = 250880.

The previous prime is 651913. The next prime is 651943. The reversal of 651920 is 29156.

It can be written as a sum of positive squares in 4 ways, for example, as 110224 + 541696 = 332^2 + 736^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

651920 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2180 + ... + 2460.

It is an arithmetic number, because the mean of its divisors is an integer number (39339).

2⁶⁵¹⁹²⁰ 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 651920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (786780).

651920 is an abundant number, since it is smaller than the sum of its proper divisors (921640).

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

651920 is a wasteful number, since it uses less digits than its factorization.

651920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 323 (or 317 counting only the distinct ones).

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 651920 is about 807.4156302673. The cubic root of 651920 is about 86.7091179276.

The spelling of 651920 in words is "six hundred fifty-one thousand, nine hundred twenty".