20345340 has 72 divisors (see below), whose sum is σ = 59644368. Its totient is φ = 5181440.

The previous prime is 20345293. The next prime is 20345357. The reversal of 20345340 is 4354302.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 31420 + ... + 32060.

It is an arithmetic number, because the mean of its divisors is an integer number (828394).

Almost surely, 2^20345340 is an apocalyptic number.

20345340 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 20345340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29822184).

20345340 is an abundant number, since it is smaller than the sum of its proper divisors (39299028).

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

20345340 is a wasteful number, since it uses less digits than its factorization.

20345340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 699 (or 674 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 21.

The square root of 20345340 is about 4510.5808938539. The cubic root of 20345340 is about 272.9951829981.

Adding to 20345340 its reverse (4354302), we get a palindrome (24699642).

The spelling of 20345340 in words is "twenty million, three hundred forty-five thousand, three hundred forty".