21101282 has 4 divisors (see below), whose sum is σ = 31651926. Its totient is φ = 10550640.

The previous prime is 21101273. The next prime is 21101287. The reversal of 21101282 is 28210112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 16168441 + 4932841 = 4021^2 + 2221^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21101282.

It is not an unprimeable number, because it can be changed into a prime (21101287) by changing a digit.

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 as a sum of consecutive naturals, namely, 5275319 + ... + 5275322.

Almost surely, 2^21101282 is an apocalyptic number.

21101282 is a deficient number, since it is larger than the sum of its proper divisors (10550644).

21101282 is a wasteful number, since it uses less digits than its factorization.

21101282 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10550643.

The product of its (nonzero) digits is 64, while the sum is 17.

The square root of 21101282 is about 4593.6131748331. The cubic root of 21101282 is about 276.3352451515.

Adding to 21101282 its reverse (28210112), we get a palindrome (49311394).

The spelling of 21101282 in words is "twenty-one million, one hundred one thousand, two hundred eighty-two".