21020000120205 has 32 divisors (see below), whose sum is σ = 34188111427968. Its totient is φ = 11025347577600.

The previous prime is 21020000120183. The next prime is 21020000120213. The reversal of 21020000120205 is 50202100002012.

It is not a de Polignac number, because 21020000120205 - 2⁵ = 21020000120173 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4977895 + ... + 8174315.

It is an arithmetic number, because the mean of its divisors is an integer number (1068378482124).

Almost surely, 2^{21020000120205} is an apocalyptic number.

It is an amenable number.

21020000120205 is a deficient number, since it is larger than the sum of its proper divisors (13168111307763).

21020000120205 is a wasteful number, since it uses less digits than its factorization.

21020000120205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3203677.

The product of its (nonzero) digits is 80, while the sum is 15.

Adding to 21020000120205 its reverse (50202100002012), we get a palindrome (71222100122217).

The spelling of 21020000120205 in words is "twenty-one trillion, twenty billion, one hundred twenty thousand, two hundred five".