20729320 has 16 divisors (see below), whose sum is σ = 46641060. Its totient is φ = 8291712.

The previous prime is 20729281. The next prime is 20729329. The reversal of 20729320 is 2392702.

It can be written as a sum of positive squares in 2 ways, for example, as 17791524 + 2937796 = 4218^2 + 1714^2 .

It is not an unprimeable number, because it can be changed into a prime (20729329) 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 3 ways as a sum of consecutive naturals, for example, 259077 + ... + 259156.

Almost surely, 2^20729320 is an apocalyptic number.

20729320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20729320 is an abundant number, since it is smaller than the sum of its proper divisors (25911740).

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

20729320 is a wasteful number, since it uses less digits than its factorization.

20729320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 518244 (or 518240 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 25.

The square root of 20729320 is about 4552.9462988267. The cubic root of 20729320 is about 274.7019139211.

The spelling of 20729320 in words is "twenty million, seven hundred twenty-nine thousand, three hundred twenty".