20012000000021 has 32 divisors (see below), whose sum is σ = 20666980873728. Its totient is φ = 19367959703040.

The previous prime is 20012000000009. The next prime is 20012000000053. The reversal of 20012000000021 is 12000000021002.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20012000000021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20011999999945 and 20012000000008.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20012000000071) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 1645311686 + ... + 1645323848.

It is an arithmetic number, because the mean of its divisors is an integer number (645843152304).

Almost surely, 2^{20012000000021} is an apocalyptic number.

It is an amenable number.

20012000000021 is a deficient number, since it is larger than the sum of its proper divisors (654980873707).

20012000000021 is a wasteful number, since it uses less digits than its factorization.

20012000000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13421.

The product of its (nonzero) digits is 8, while the sum is 8.

Adding to 20012000000021 its reverse (12000000021002), we get a palindrome (32012000021023).

The spelling of 20012000000021 in words is "twenty trillion, twelve billion, twenty-one", and thus it is an aban number and an uban number.