20389740 has 96 divisors (see below), whose sum is σ = 66823680. Its totient is φ = 4548096.

The previous prime is 20389729. The next prime is 20389741. The reversal of 20389740 is 4798302.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20389741) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17496 + ... + 18624.

It is an arithmetic number, because the mean of its divisors is an integer number (696080).

Almost surely, 2^20389740 is an apocalyptic number.

20389740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is a pronic number, being equal to 4515×4516.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20389740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33411840).

20389740 is an abundant number, since it is smaller than the sum of its proper divisors (46433940).

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

20389740 is a wasteful number, since it uses less digits than its factorization.

20389740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1191 (or 1189 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 33.

The square root of 20389740 is about 4515.4999723176. The cubic root of 20389740 is about 273.1936261390.

The spelling of 20389740 in words is "twenty million, three hundred eighty-nine thousand, seven hundred forty".