20203440 has 40 divisors (see below), whose sum is σ = 62631408. Its totient is φ = 5387520.

The previous prime is 20203427. The next prime is 20203457. The reversal of 20203440 is 4430202.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41851 + ... + 42330.

Almost surely, 2^20203440 is an apocalyptic number.

20203440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20203440 is an abundant number, since it is smaller than the sum of its proper divisors (42427968).

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

20203440 is a wasteful number, since it uses less digits than its factorization.

20203440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84197 (or 84191 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 15.

The square root of 20203440 is about 4494.8236895344. The cubic root of 20203440 is about 272.3590270463.

Adding to 20203440 its reverse (4430202), we get a palindrome (24633642).

It can be divided in two parts, 2020 and 3440, that added together give a triangular number (5460 = T₁₀₄).

The spelling of 20203440 in words is "twenty million, two hundred three thousand, four hundred forty".