20135442400 has 144 divisors (see below), whose sum is σ = 52492890240. Its totient is φ = 7525324800.

The previous prime is 20135442373. The next prime is 20135442401. The reversal of 20135442400 is 424453102.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20135442401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 705202 + ... + 733198.

It is an arithmetic number, because the mean of its divisors is an integer number (364533960).

Almost surely, 2^20135442400 is an apocalyptic number.

20135442400 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 20135442400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26246445120).

20135442400 is an abundant number, since it is smaller than the sum of its proper divisors (32357447840).

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

20135442400 is a wasteful number, since it uses less digits than its factorization.

20135442400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28077 (or 28064 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 25.

Adding to 20135442400 its reverse (424453102), we get a palindrome (20559895502).

The spelling of 20135442400 in words is "twenty billion, one hundred thirty-five million, four hundred forty-two thousand, four hundred".