21011042 has 16 divisors (see below), whose sum is σ = 34859832. Its totient is φ = 9434880.

The previous prime is 21011033. The next prime is 21011063. The reversal of 21011042 is 24011012.

It can be written as a sum of positive squares in 4 ways, for example, as 11282881 + 9728161 = 3359^2 + 3119^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9959 + ... + 11882.

Almost surely, 2^21011042 is an apocalyptic number.

21011042 is a deficient number, since it is larger than the sum of its proper divisors (13848790).

21011042 is a wasteful number, since it uses less digits than its factorization.

21011042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21893.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 21011042 is about 4583.7803175981. The cubic root of 21011042 is about 275.9407647856.

Adding to 21011042 its reverse (24011012), we get a palindrome (45022054).

It can be divided in two parts, 2 and 1011042, that multiplied together give a square (2022084 = 1422²).

The spelling of 21011042 in words is "twenty-one million, eleven thousand, forty-two".