21403200420 has 144 divisors (see below), whose sum is σ = 76591377408. Its totient is φ = 4734339840.

The previous prime is 21403200419. The next prime is 21403200443. The reversal of 21403200420 is 2400230412.

21403200420 is a `hidden beast` number, since 2 + 1 + 40 + 3 + 200 + 420 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 21403200393 and 21403200402.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 234919 + ... + 313038.

Almost surely, 2^21403200420 is an apocalyptic number.

21403200420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21403200420 is an abundant number, since it is smaller than the sum of its proper divisors (55188176988).

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

21403200420 is a wasteful number, since it uses less digits than its factorization.

21403200420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 548010 (or 548005 counting only the distinct ones).

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

Adding to 21403200420 its reverse (2400230412), we get a palindrome (23803430832).

The spelling of 21403200420 in words is "twenty-one billion, four hundred three million, two hundred thousand, four hundred twenty".