20400104340 has 720 divisors, whose sum is σ = 82758703104. Its totient is φ = 4158604800.

The previous prime is 20400104303. The next prime is 20400104353. The reversal of 20400104340 is 4340100402.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 53263789 + ... + 53264171.

Almost surely, 2^20400104340 is an apocalyptic number.

20400104340 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 20400104340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41379351552).

20400104340 is an abundant number, since it is smaller than the sum of its proper divisors (62358598764).

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

20400104340 is a wasteful number, since it uses less digits than its factorization.

20400104340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 490 (or 472 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

Adding to 20400104340 its reverse (4340100402), we get a palindrome (24740204742).

The spelling of 20400104340 in words is "twenty billion, four hundred million, one hundred four thousand, three hundred forty".