20399504800 has 144 divisors (see below), whose sum is σ = 51761687040. Its totient is φ = 7841111040.

The previous prime is 20399504789. The next prime is 20399504809. The reversal of 20399504800 is 840599302.

It is a happy number.

It is a super-2 number, since 2×20399504800² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (20399504809) 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, 5171629 + ... + 5175571.

It is an arithmetic number, because the mean of its divisors is an integer number (359456160).

Almost surely, 2^20399504800 is an apocalyptic number.

20399504800 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 20399504800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25880843520).

20399504800 is an abundant number, since it is smaller than the sum of its proper divisors (31362182240).

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

20399504800 is a wasteful number, since it uses less digits than its factorization.

20399504800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4215 (or 4202 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 40.

The spelling of 20399504800 in words is "twenty billion, three hundred ninety-nine million, five hundred four thousand, eight hundred".