21213545104042 has 16 divisors (see below), whose sum is σ = 33734530317312. Its totient is φ = 9987196473360.

The previous prime is 21213545103991. The next prime is 21213545104061. The reversal of 21213545104042 is 24040154531212.

It is a junction number, because it is equal to n+sod(n) for n = 21213545103989 and 21213545104007.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4623699778 + ... + 4623704365.

It is an arithmetic number, because the mean of its divisors is an integer number (2108408144832).

Almost surely, 2^{21213545104042} is an apocalyptic number.

21213545104042 is a deficient number, since it is larger than the sum of its proper divisors (12520985213270).

21213545104042 is a wasteful number, since it uses less digits than its factorization.

21213545104042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9247404213.

The product of its (nonzero) digits is 38400, while the sum is 34.

Adding to 21213545104042 its reverse (24040154531212), we get a palindrome (45253699635254).

The spelling of 21213545104042 in words is "twenty-one trillion, two hundred thirteen billion, five hundred forty-five million, one hundred four thousand, forty-two".