21255150 has 96 divisors (see below), whose sum is σ = 62281728. Its totient is φ = 4694400.

The previous prime is 21255133. The next prime is 21255161. The reversal of 21255150 is 5155212.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 32224 + ... + 32876.

It is an arithmetic number, because the mean of its divisors is an integer number (648768).

Almost surely, 2^21255150 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21255150, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31140864).

21255150 is an abundant number, since it is smaller than the sum of its proper divisors (41026578).

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

21255150 is a wasteful number, since it uses less digits than its factorization.

21255150 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 706 (or 701 counting only the distinct ones).

The product of its (nonzero) digits is 500, while the sum is 21.

The square root of 21255150 is about 4610.3307907351. The cubic root of 21255150 is about 277.0052869049.

The spelling of 21255150 in words is "twenty-one million, two hundred fifty-five thousand, one hundred fifty".