20400000000 has 396 divisors, whose sum is σ = 71964806904. Its totient is φ = 5120000000.

The previous prime is 20399999999. The next prime is 20400000001. The reversal of 20400000000 is 402.

It is an interprime number because it is at equal distance from previous prime (20399999999) and next prime (20400000001).

It is a Harshad number since it is a multiple of its sum of digits (6).

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

It is not an unprimeable number, because it can be changed into a prime (20400000001) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1199999992 + ... + 1200000008.

Almost surely, 2^20400000000 is an apocalyptic number.

20400000000 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 20400000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35982403452).

20400000000 is an abundant number, since it is smaller than the sum of its proper divisors (51564806904).

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

20400000000 is an frugal number, since it uses more digits than its factorization.

20400000000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80 (or 27 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 6.

Adding to 20400000000 its reverse (402), we get a palindrome (20400000402).

It can be divided in two parts, 20 and 400000000, that multiplied together give a cube (8000000000 = 2000³).

The spelling of 20400000000 in words is "twenty billion, four hundred million", and thus it is an aban number.