20103840 has 144 divisors (see below), whose sum is σ = 71705088. Its totient is φ = 5119488.

The previous prime is 20103821. The next prime is 20103859. The reversal of 20103840 is 4830102.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20103821) and next prime (20103859).

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (18).

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, 32817 + ... + 33423.

It is an arithmetic number, because the mean of its divisors is an integer number (497952).

Almost surely, 2^20103840 is an apocalyptic number.

20103840 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 20103840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35852544).

20103840 is an abundant number, since it is smaller than the sum of its proper divisors (51601248).

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

20103840 is a wasteful number, since it uses less digits than its factorization.

20103840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 651 (or 640 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 20103840 is about 4483.7305895872. The cubic root of 20103840 is about 271.9107261811.

Adding to 20103840 its reverse (4830102), we get a palindrome (24933942).

The spelling of 20103840 in words is "twenty million, one hundred three thousand, eight hundred forty".