20400200400 has 240 divisors, whose sum is σ = 66665108160. Its totient is φ = 5331456000.

The previous prime is 20400200389. The next prime is 20400200407. The reversal of 20400200400 is 400200402.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20400200407) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 15679750 + ... + 15681050.

It is an arithmetic number, because the mean of its divisors is an integer number (277771284).

Almost surely, 2^20400200400 is an apocalyptic number.

20400200400 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 20400200400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33332554080).

20400200400 is an abundant number, since it is smaller than the sum of its proper divisors (46264907760).

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

20400200400 is a wasteful number, since it uses less digits than its factorization.

20400200400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1574 (or 1563 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 12.

Adding to 20400200400 its reverse (400200402), we get a palindrome (20800400802).

The spelling of 20400200400 in words is "twenty billion, four hundred million, two hundred thousand, four hundred".