20168240 has 80 divisors (see below), whose sum is σ = 49871808. Its totient is φ = 7569408.

The previous prime is 20168237. The next prime is 20168243. The reversal of 20168240 is 4286102.

It is an interprime number because it is at equal distance from previous prime (20168237) and next prime (20168243).

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20168243) 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, 178424 + ... + 178536.

Almost surely, 2^20168240 is an apocalyptic number.

20168240 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 20168240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24935904).

20168240 is an abundant number, since it is smaller than the sum of its proper divisors (29703568).

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

20168240 is a wasteful number, since it uses less digits than its factorization.

20168240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246 (or 240 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 20168240 is about 4490.9063673161. The cubic root of 20168240 is about 272.2007600893.

The spelling of 20168240 in words is "twenty million, one hundred sixty-eight thousand, two hundred forty".