21001040242 has 48 divisors (see below), whose sum is σ = 39483303552. Its totient is φ = 8303934240.

The previous prime is 21001040237. The next prime is 21001040251. The reversal of 21001040242 is 24204010012.

It is a super-2 number, since 2×21001040242² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4256517 + ... + 4261447.

It is an arithmetic number, because the mean of its divisors is an integer number (822568824).

Almost surely, 2^21001040242 is an apocalyptic number.

21001040242 is a deficient number, since it is larger than the sum of its proper divisors (18482263310).

21001040242 is a wasteful number, since it uses less digits than its factorization.

21001040242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8303 (or 8296 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21001040242 its reverse (24204010012), we get a palindrome (45205050254).

The spelling of 21001040242 in words is "twenty-one billion, one million, forty thousand, two hundred forty-two".