20400242000 has 80 divisors (see below), whose sum is σ = 49453961232. Its totient is φ = 8139225600.

The previous prime is 20400241997. The next prime is 20400242003. The reversal of 20400242000 is 24200402.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20400241997) and next prime (20400242003).

It can be written as a sum of positive squares in 8 ways, for example, as 1727566096 + 18672675904 = 41564^2 + 136648^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20400242003) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 781154 + ... + 806846.

Almost surely, 2^20400242000 is an apocalyptic number.

20400242000 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 20400242000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24726980616).

20400242000 is an abundant number, since it is smaller than the sum of its proper divisors (29053719232).

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

20400242000 is a wasteful number, since it uses less digits than its factorization.

20400242000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26113 (or 26097 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 14.

Adding to 20400242000 its reverse (24200402), we get a palindrome (20424442402).

The spelling of 20400242000 in words is "twenty billion, four hundred million, two hundred forty-two thousand".