20320740 has 144 divisors (see below), whose sum is σ = 69713280. Its totient is φ = 4910400.

The previous prime is 20320739. The next prime is 20320757. The reversal of 20320740 is 4702302.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

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 47 ways as a sum of consecutive naturals, for example, 65185 + ... + 65495.

It is an arithmetic number, because the mean of its divisors is an integer number (484120).

Almost surely, 2^20320740 is an apocalyptic number.

20320740 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 20320740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34856640).

20320740 is an abundant number, since it is smaller than the sum of its proper divisors (49392540).

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

20320740 is a wasteful number, since it uses less digits than its factorization.

20320740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 351 (or 332 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 18.

The square root of 20320740 is about 4507.8531475637. The cubic root of 20320740 is about 272.8851104538.

The spelling of 20320740 in words is "twenty million, three hundred twenty thousand, seven hundred forty".