21129150 has 48 divisors (see below), whose sum is σ = 59889024. Its totient is φ = 4829280.

The previous prime is 21129137. The next prime is 21129151. The reversal of 21129150 is 5192112.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21129151) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9012 + ... + 11111.

It is an arithmetic number, because the mean of its divisors is an integer number (1247688).

Almost surely, 2^21129150 is an apocalyptic number.

21129150 is an abundant number, since it is smaller than the sum of its proper divisors (38759874).

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

21129150 is a wasteful number, since it uses less digits than its factorization.

21129150 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20145 (or 20140 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 21.

The square root of 21129150 is about 4596.6455160258. The cubic root of 21129150 is about 276.4568416016.

The spelling of 21129150 in words is "twenty-one million, one hundred twenty-nine thousand, one hundred fifty".