20807140 has 24 divisors (see below), whose sum is σ = 43925112. Its totient is φ = 8279040.

The previous prime is 20807093. The next prime is 20807153. The reversal of 20807140 is 4170802.

It can be written as a sum of positive squares in 4 ways, for example, as 3717184 + 17089956 = 1928^2 + 4134^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1300 + ... + 6580.

It is an arithmetic number, because the mean of its divisors is an integer number (1830213).

Almost surely, 2^20807140 is an apocalyptic number.

20807140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20807140 is an abundant number, since it is smaller than the sum of its proper divisors (23117972).

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

20807140 is a wasteful number, since it uses less digits than its factorization.

20807140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5487 (or 5485 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 20807140 is about 4561.4844075147. The cubic root of 20807140 is about 275.0452377370.

Adding to 20807140 its reverse (4170802), we get a palindrome (24977942).

The spelling of 20807140 in words is "twenty million, eight hundred seven thousand, one hundred forty".