657001220 has 48 divisors (see below), whose sum is σ = 1416922416. Its totient is φ = 255744000.

The previous prime is 657001217. The next prime is 657001223. The reversal of 657001220 is 22100756.

It is an interprime number because it is at equal distance from previous prime (657001217) and next prime (657001223).

It can be written as a sum of positive squares in 8 ways, for example, as 119596096 + 537405124 = 10936^2 + 23182^2 .

It is not an unprimeable number, because it can be changed into a prime (657001223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 442880 + ... + 444360.

It is an arithmetic number, because the mean of its divisors is an integer number (29519217).

Almost surely, 2^657001220 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 657001220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (708461208).

657001220 is an abundant number, since it is smaller than the sum of its proper divisors (759921196).

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

657001220 is a wasteful number, since it uses less digits than its factorization.

657001220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2072 (or 2070 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 657001220 is about 25632.0350343081. The cubic root of 657001220 is about 869.3381234420.

Adding to 657001220 its reverse (22100756), we get a palindrome (679101976).

The spelling of 657001220 in words is "six hundred fifty-seven million, one thousand, two hundred twenty".