215421020420 has 12 divisors (see below), whose sum is σ = 452384142924. Its totient is φ = 86168408160.

The previous prime is 215421020407. The next prime is 215421020447. The reversal of 215421020420 is 24020124512.

It can be written as a sum of positive squares in 2 ways, for example, as 78664542784 + 136756477636 = 280472^2 + 369806^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5385525491 + ... + 5385525530.

It is an arithmetic number, because the mean of its divisors is an integer number (37698678577).

Almost surely, 2^215421020420 is an apocalyptic number.

215421020420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215421020420 is an abundant number, since it is smaller than the sum of its proper divisors (236963122504).

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

215421020420 is a wasteful number, since it uses less digits than its factorization.

215421020420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10771051030 (or 10771051028 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 23.

Adding to 215421020420 its reverse (24020124512), we get a palindrome (239441144932).

The spelling of 215421020420 in words is "two hundred fifteen billion, four hundred twenty-one million, twenty thousand, four hundred twenty".