21115563413420 has 36 divisors (see below), whose sum is σ = 51582304912320. Its totient is φ = 7239621741408.

The previous prime is 21115563413377. The next prime is 21115563413423. The reversal of 21115563413420 is 2431436551112.

It is a super-2 number, since 2×21115563413420² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21115563413423) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10773245660 + ... + 10773247619.

It is an arithmetic number, because the mean of its divisors is an integer number (1432841803120).

Almost surely, 2^{21115563413420} is an apocalyptic number.

21115563413420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21115563413420 is an abundant number, since it is smaller than the sum of its proper divisors (30466741498900).

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

21115563413420 is a wasteful number, since it uses less digits than its factorization.

21115563413420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21546493302 (or 21546493293 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 38.

Adding to 21115563413420 its reverse (2431436551112), we get a palindrome (23546999964532).

The spelling of 21115563413420 in words is "twenty-one trillion, one hundred fifteen billion, five hundred sixty-three million, four hundred thirteen thousand, four hundred twenty".