20021211210001 has 4 divisors (see below), whose sum is σ = 20204892046900. Its totient is φ = 19837530373104.

The previous prime is 20021211209983. The next prime is 20021211210031. The reversal of 20021211210001 is 10001211212002.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14207320947600 + 5813890262401 = 3769260^2 + 2411201^2 .

It is a cyclic number.

It is not a de Polignac number, because 20021211210001 - 2⁷ = 20021211209873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20021211210031) 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 3 ways as a sum of consecutive naturals, for example, 91840418286 + ... + 91840418503.

It is an arithmetic number, because the mean of its divisors is an integer number (5051223011725).

Almost surely, 2^{20021211210001} is an apocalyptic number.

It is an amenable number.

20021211210001 is a deficient number, since it is larger than the sum of its proper divisors (183680836899).

20021211210001 is a wasteful number, since it uses less digits than its factorization.

20021211210001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183680836898.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 20021211210001 its reverse (10001211212002), we get a palindrome (30022422422003).

The spelling of 20021211210001 in words is "twenty trillion, twenty-one billion, two hundred eleven million, two hundred ten thousand, one".