20450720 has 24 divisors (see below), whose sum is σ = 48315204. Its totient is φ = 8180224.

The previous prime is 20450719. The next prime is 20450737. The reversal of 20450720 is 2705402.

It can be written as a sum of positive squares in 2 ways, for example, as 19114384 + 1336336 = 4372^2 + 1156^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 20450692 and 20450701.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63749 + ... + 64068.

Almost surely, 2^20450720 is an apocalyptic number.

20450720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20450720 is an abundant number, since it is smaller than the sum of its proper divisors (27864484).

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

20450720 is a wasteful number, since it uses less digits than its factorization.

20450720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127832 (or 127824 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 20.

The square root of 20450720 is about 4522.2472289781. The cubic root of 20450720 is about 273.4657036160.

The spelling of 20450720 in words is "twenty million, four hundred fifty thousand, seven hundred twenty".