21100254 has 32 divisors (see below), whose sum is σ = 49144320. Its totient is φ = 5914272.

The previous prime is 21100253. The next prime is 21100267. The reversal of 21100254 is 45200112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100253) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2514 + ... + 6965.

It is an arithmetic number, because the mean of its divisors is an integer number (1535760).

Almost surely, 2^21100254 is an apocalyptic number.

21100254 is an abundant number, since it is smaller than the sum of its proper divisors (28044066).

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

21100254 is a wasteful number, since it uses less digits than its factorization.

21100254 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9544.

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 21100254 is about 4593.5012789810. The cubic root of 21100254 is about 276.3307576319.

Adding to 21100254 its reverse (45200112), we get a palindrome (66300366).

The spelling of 21100254 in words is "twenty-one million, one hundred thousand, two hundred fifty-four".