20209340 has 12 divisors (see below), whose sum is σ = 42439656. Its totient is φ = 8083728.

The previous prime is 20209339. The next prime is 20209367. The reversal of 20209340 is 4390202.

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 1010467 = 20209340 / (2 + 0 + 2 + 0 + 9 + 3 + 4 + 0).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 505214 + ... + 505253.

It is an arithmetic number, because the mean of its divisors is an integer number (3536638).

Almost surely, 2^20209340 is an apocalyptic number.

20209340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20209340 is an abundant number, since it is smaller than the sum of its proper divisors (22230316).

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

20209340 is a wasteful number, since it uses less digits than its factorization.

20209340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1010476 (or 1010474 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 20209340 is about 4495.4799521297. The cubic root of 20209340 is about 272.3855367539.

Adding to 20209340 its reverse (4390202), we get a palindrome (24599542).

The spelling of 20209340 in words is "twenty million, two hundred nine thousand, three hundred forty".