21020020000042 has 32 divisors (see below), whose sum is σ = 36926608707072. Its totient is φ = 8786816168064.

The previous prime is 21020019999991. The next prime is 21020020000043. The reversal of 21020020000042 is 24000002002012.

It is a junction number, because it is equal to n+sod(n) for n = 21020019999977 and 21020020000031.

It is not an unprimeable number, because it can be changed into a prime (21020020000043) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54321403 + ... + 54706990.

It is an arithmetic number, because the mean of its divisors is an integer number (1153956522096).

Almost surely, 2^{21020020000042} is an apocalyptic number.

21020020000042 is a deficient number, since it is larger than the sum of its proper divisors (15906588707030).

21020020000042 is a wasteful number, since it uses less digits than its factorization.

21020020000042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109028742.

The product of its (nonzero) digits is 64, while the sum is 13.

Adding to 21020020000042 its reverse (24000002002012), we get a palindrome (45020022002054).

The spelling of 21020020000042 in words is "twenty-one trillion, twenty billion, twenty million, forty-two", and thus it is an aban number and an uban number.