21010249 has 24 divisors (see below), whose sum is σ = 24665472. Its totient is φ = 17821440.

The previous prime is 21010237. The next prime is 21010259. The reversal of 21010249 is 94201012.

It is not a de Polignac number, because 21010249 - 2⁵ = 21010217 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010229) 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, 203932 + ... + 204034.

It is an arithmetic number, because the mean of its divisors is an integer number (1027728).

Almost surely, 2^21010249 is an apocalyptic number.

It is an amenable number.

21010249 is a deficient number, since it is larger than the sum of its proper divisors (3655223).

21010249 is a wasteful number, since it uses less digits than its factorization.

21010249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 217 (or 204 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 21010249 is about 4583.6938161269. The cubic root of 21010249 is about 275.9372932176.

The spelling of 21010249 in words is "twenty-one million, ten thousand, two hundred forty-nine".