21100242 has 16 divisors (see below), whose sum is σ = 42246432. Its totient is φ = 7025760.

The previous prime is 21100231. The next prime is 21100253. The reversal of 21100242 is 24200112.

It is an interprime number because it is at equal distance from previous prime (21100231) and next prime (21100253).

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 7 ways as a sum of consecutive naturals, for example, 8038 + ... + 10334.

It is an arithmetic number, because the mean of its divisors is an integer number (2640402).

Almost surely, 2^21100242 is an apocalyptic number.

It is a pronic number, being equal to 4593×4594.

21100242 is an abundant number, since it is smaller than the sum of its proper divisors (21146190).

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

21100242 is a wasteful number, since it uses less digits than its factorization.

21100242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3833.

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 21100242 is about 4593.4999727876. The cubic root of 21100242 is about 276.3307052476.

Adding to 21100242 its reverse (24200112), we get a palindrome (45300354).

The spelling of 21100242 in words is "twenty-one million, one hundred thousand, two hundred forty-two".