21020019999999 has 16 divisors (see below), whose sum is σ = 28205760083040. Its totient is φ = 13923816791040.

The previous prime is 21020019999991. The next prime is 21020020000043. The reversal of 21020019999999 is 99999991002012.

It is not a de Polignac number, because 21020019999999 - 2³ = 21020019999991 is a prime.

21020019999999 is a modest number, since divided by 9999999 gives 2102001 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020019999991) 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, 25216519 + ... + 26036759.

It is an arithmetic number, because the mean of its divisors is an integer number (1762860005190).

Almost surely, 2^{21020019999999} is an apocalyptic number.

21020019999999 is a deficient number, since it is larger than the sum of its proper divisors (7185740083041).

21020019999999 is a wasteful number, since it uses less digits than its factorization.

21020019999999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 874810.

The product of its (nonzero) digits is 19131876, while the sum is 69.

The spelling of 21020019999999 in words is "twenty-one trillion, twenty billion, nineteen million, nine hundred ninety-nine thousand, nine hundred ninety-nine".