20730140 has 48 divisors (see below), whose sum is σ = 48535200. Its totient is φ = 7391232.

The previous prime is 20730131. The next prime is 20730167. The reversal of 20730140 is 4103702.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4856 + ... + 8064.

It is an arithmetic number, because the mean of its divisors is an integer number (1011150).

Almost surely, 2^20730140 is an apocalyptic number.

20730140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20730140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24267600).

20730140 is an abundant number, since it is smaller than the sum of its proper divisors (27805060).

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

20730140 is a wasteful number, since it uses less digits than its factorization.

20730140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3254 (or 3252 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 17.

The square root of 20730140 is about 4553.0363495145. The cubic root of 20730140 is about 274.7055360467.

Adding to 20730140 its reverse (4103702), we get a palindrome (24833842).

The spelling of 20730140 in words is "twenty million, seven hundred thirty thousand, one hundred forty".