20021212005 has 16 divisors (see below), whose sum is σ = 32047868160. Its totient is φ = 10673336768.

The previous prime is 20021211989. The next prime is 20021212007. The reversal of 20021212005 is 50021212002.

It is a cyclic number.

It is not a de Polignac number, because 20021212005 - 2⁴ = 20021211989 is a prime.

It is a super-2 number, since 2×20021212005² (a number of 21 digits) contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021212007) 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 15 ways as a sum of consecutive naturals, for example, 254397 + ... + 323666.

It is an arithmetic number, because the mean of its divisors is an integer number (2002991760).

Almost surely, 2^20021212005 is an apocalyptic number.

It is an amenable number.

20021212005 is a deficient number, since it is larger than the sum of its proper divisors (12026656155).

20021212005 is a wasteful number, since it uses less digits than its factorization.

20021212005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 580380.

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

Adding to 20021212005 its reverse (50021212002), we get a palindrome (70042424007).

The spelling of 20021212005 in words is "twenty billion, twenty-one million, two hundred twelve thousand, five".