20415340 has 48 divisors (see below), whose sum is σ = 47464704. Its totient is φ = 7313600.

The previous prime is 20415319. The next prime is 20415341. The reversal of 20415340 is 4351402.

It is a super-2 number, since 2×20415340² = 833572214631200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20415341) 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 15 ways as a sum of consecutive naturals, for example, 14967 + ... + 16273.

It is an arithmetic number, because the mean of its divisors is an integer number (988848).

Almost surely, 2^20415340 is an apocalyptic number.

20415340 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 20415340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23732352).

20415340 is an abundant number, since it is smaller than the sum of its proper divisors (27049364).

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

20415340 is a wasteful number, since it uses less digits than its factorization.

20415340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1398 (or 1396 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 20415340 is about 4518.3337636788. Note that the first 3 decimals coincide. The cubic root of 20415340 is about 273.3079128980.

Adding to 20415340 its reverse (4351402), we get a palindrome (24766742).

It can be divided in two parts, 2041 and 5340, that added together give a triangular number (7381 = T₁₂₁).

The spelling of 20415340 in words is "twenty million, four hundred fifteen thousand, three hundred forty".