308640020 has 48 divisors (see below), whose sum is σ = 702540048. Its totient is φ = 113218560.

The previous prime is 308640001. The next prime is 308640029. The reversal of 308640020 is 20046803.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 73753744 + 234886276 = 8588^2 + 15326^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (308640029) 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, 37040 + ... + 44600.

It is an arithmetic number, because the mean of its divisors is an integer number (14636251).

Almost surely, 2^308640020 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 308640020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (351270024).

308640020 is an abundant number, since it is smaller than the sum of its proper divisors (393900028).

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

308640020 is a wasteful number, since it uses less digits than its factorization.

308640020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7740 (or 7738 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 308640020 is about 17568.1535740100. The cubic root of 308640020 is about 675.7987946175.

Adding to 308640020 its reverse (20046803), we get a palindrome (328686823).

The spelling of 308640020 in words is "three hundred eight million, six hundred forty thousand, twenty".