21215150 has 48 divisors (see below), whose sum is σ = 45599760. Its totient is φ = 7257600.

The previous prime is 21215147. The next prime is 21215203. The reversal of 21215150 is 5151212.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8216 + ... + 10484.

It is an arithmetic number, because the mean of its divisors is an integer number (949995).

Almost surely, 2^21215150 is an apocalyptic number.

21215150 is an abundant number, since it is smaller than the sum of its proper divisors (24384610).

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

21215150 is a wasteful number, since it uses less digits than its factorization.

21215150 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2309 (or 2304 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 17.

The square root of 21215150 is about 4605.9906643414. The cubic root of 21215150 is about 276.8314126617.

Adding to 21215150 its reverse (5151212), we get a palindrome (26366362).

The spelling of 21215150 in words is "twenty-one million, two hundred fifteen thousand, one hundred fifty".