215421020 has 12 divisors (see below), whose sum is σ = 452384184. Its totient is φ = 86168400.

The previous prime is 215421007. The next prime is 215421023. The reversal of 215421020 is 20124512.

215421020 is nontrivially palindromic in base 11.

It is a self number, because there is not a number n which added to its sum of digits gives 215421020.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215421023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5385506 + ... + 5385545.

It is an arithmetic number, because the mean of its divisors is an integer number (37698682).

Almost surely, 2^215421020 is an apocalyptic number.

215421020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215421020 is an abundant number, since it is smaller than the sum of its proper divisors (236963164).

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

215421020 is a wasteful number, since it uses less digits than its factorization.

215421020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10771060 (or 10771058 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 215421020 is about 14677.2279399075. The cubic root of 215421020 is about 599.4634277007.

Adding to 215421020 its reverse (20124512), we get a palindrome (235545532).

The spelling of 215421020 in words is "two hundred fifteen million, four hundred twenty-one thousand, twenty".