21287150 has 24 divisors (see below), whose sum is σ = 40518984. Its totient is φ = 8316000.

The previous prime is 21287143. The next prime is 21287209. The reversal of 21287150 is 5178212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2801 + ... + 7100.

It is an arithmetic number, because the mean of its divisors is an integer number (1688291).

Almost surely, 2^21287150 is an apocalyptic number.

21287150 is a deficient number, since it is larger than the sum of its proper divisors (19231834).

21287150 is a wasteful number, since it uses less digits than its factorization.

21287150 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9956 (or 9951 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 26.

The square root of 21287150 is about 4613.7999523170. The cubic root of 21287150 is about 277.1442293025.

The spelling of 21287150 in words is "twenty-one million, two hundred eighty-seven thousand, one hundred fifty".