20700240 has 80 divisors (see below), whose sum is σ = 70013376. Its totient is φ = 5017600.

The previous prime is 20700233. The next prime is 20700269. The reversal of 20700240 is 4200702.

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 (15).

It is a congruent number.

It is an unprimeable number.

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, 1281 + ... + 6560.

Almost surely, 2^20700240 is an apocalyptic number.

20700240 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 20700240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35006688).

20700240 is an abundant number, since it is smaller than the sum of its proper divisors (49313136).

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

20700240 is a wasteful number, since it uses less digits than its factorization.

20700240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7868 (or 7862 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 15.

The square root of 20700240 is about 4549.7516415734. The cubic root of 20700240 is about 274.5733991727.

Adding to 20700240 its reverse (4200702), we get a palindrome (24900942).

The spelling of 20700240 in words is "twenty million, seven hundred thousand, two hundred forty".