20783240 has 16 divisors (see below), whose sum is σ = 46762380. Its totient is φ = 8313280.

The previous prime is 20783239. The next prime is 20783267. The reversal of 20783240 is 4238702.

It can be written as a sum of positive squares in 2 ways, for example, as 20376196 + 407044 = 4514^2 + 638^2 .

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, 259751 + ... + 259830.

Almost surely, 2^20783240 is an apocalyptic number.

20783240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20783240 is an abundant number, since it is smaller than the sum of its proper divisors (25979140).

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

20783240 is a wasteful number, since it uses less digits than its factorization.

20783240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 519592 (or 519588 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 26.

The square root of 20783240 is about 4558.8638935594. The cubic root of 20783240 is about 274.9398876874.

The spelling of 20783240 in words is "twenty million, seven hundred eighty-three thousand, two hundred forty".