20400355420 has 24 divisors (see below), whose sum is σ = 42854256144. Its totient is φ = 8157568896.

The previous prime is 20400355387. The next prime is 20400355429. The reversal of 20400355420 is 2455300402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20400355429) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 95169 + ... + 223288.

It is an arithmetic number, because the mean of its divisors is an integer number (1785594006).

Almost surely, 2^20400355420 is an apocalyptic number.

20400355420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20400355420 is an abundant number, since it is smaller than the sum of its proper divisors (22453900724).

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

20400355420 is a wasteful number, since it uses less digits than its factorization.

20400355420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321669 (or 321667 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 25.

Adding to 20400355420 its reverse (2455300402), we get a palindrome (22855655822).

The spelling of 20400355420 in words is "twenty billion, four hundred million, three hundred fifty-five thousand, four hundred twenty".