21163042 has 4 divisors (see below), whose sum is σ = 31744566. Its totient is φ = 10581520.

The previous prime is 21163033. The next prime is 21163057. The reversal of 21163042 is 24036112.

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., 20079361 + 1083681 = 4481^2 + 1041^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5290759 + ... + 5290762.

Almost surely, 2^21163042 is an apocalyptic number.

21163042 is a deficient number, since it is larger than the sum of its proper divisors (10581524).

21163042 is a wasteful number, since it uses less digits than its factorization.

21163042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10581523.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 21163042 is about 4600.3306402910. The cubic root of 21163042 is about 276.6045785741.

Adding to 21163042 its reverse (24036112), we get a palindrome (45199154).

The spelling of 21163042 in words is "twenty-one million, one hundred sixty-three thousand, forty-two".