20209380 has 24 divisors (see below), whose sum is σ = 56586432. Its totient is φ = 5389152.

The previous prime is 20209367. The next prime is 20209381. The reversal of 20209380 is 8390202.

It is a self number, because there is not a number n which added to its sum of digits gives 20209380.

It is not an unprimeable number, because it can be changed into a prime (20209381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 168352 + ... + 168471.

It is an arithmetic number, because the mean of its divisors is an integer number (2357768).

Almost surely, 2^20209380 is an apocalyptic number.

20209380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20209380 is an abundant number, since it is smaller than the sum of its proper divisors (36377052).

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

20209380 is a wasteful number, since it uses less digits than its factorization.

20209380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 336835 (or 336833 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 20209380 is about 4495.4844010407. The cubic root of 20209380 is about 272.3857164631.

Adding to 20209380 its reverse (8390202), we get a palindrome (28599582).

The spelling of 20209380 in words is "twenty million, two hundred nine thousand, three hundred eighty".