21215010 has 32 divisors (see below), whose sum is σ = 51210432. Its totient is φ = 5624640.

The previous prime is 21215009. The next prime is 21215017. The reversal of 21215010 is 1051212.

It is not an unprimeable number, because it can be changed into a prime (21215017) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3477 + ... + 7383.

It is an arithmetic number, because the mean of its divisors is an integer number (1600326).

Almost surely, 2^21215010 is an apocalyptic number.

21215010 is an abundant number, since it is smaller than the sum of its proper divisors (29995422).

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

21215010 is a wasteful number, since it uses less digits than its factorization.

21215010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4098.

The product of its (nonzero) digits is 20, while the sum is 12.

The square root of 21215010 is about 4605.9754667171. The cubic root of 21215010 is about 276.8308037182.

Adding to 21215010 its reverse (1051212), we get a palindrome (22266222).

The spelling of 21215010 in words is "twenty-one million, two hundred fifteen thousand, ten".