21042682 has 16 divisors (see below), whose sum is σ = 32299272. Its totient is φ = 10278720.

The previous prime is 21042649. The next prime is 21042689. The reversal of 21042682 is 28624012.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 19722481 + 1320201 = 4441^2 + 1149^2 .

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (21042689) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20608 + ... + 21604.

Almost surely, 2^21042682 is an apocalyptic number.

21042682 is a deficient number, since it is larger than the sum of its proper divisors (11256590).

21042682 is a wasteful number, since it uses less digits than its factorization.

21042682 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1233.

The product of its (nonzero) digits is 1536, while the sum is 25.

The square root of 21042682 is about 4587.2303190487. The cubic root of 21042682 is about 276.0792060709.

Adding to 21042682 its reverse (28624012), we get a palindrome (49666694).

The spelling of 21042682 in words is "twenty-one million, forty-two thousand, six hundred eighty-two".