21020200222001 has 4 divisors (see below), whose sum is σ = 21020224767732. Its totient is φ = 21020175676272.

The previous prime is 21020200221997. The next prime is 21020200222003. The reversal of 21020200222001 is 10022200202012.

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 15140472437776 + 5879727784225 = 3891076^2 + 2424815^2 .

It is a cyclic number.

It is not a de Polignac number, because 21020200222001 - 2² = 21020200221997 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21020200222003) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10940066 + ... + 12717131.

It is an arithmetic number, because the mean of its divisors is an integer number (5255056191933).

Almost surely, 2^{21020200222001} is an apocalyptic number.

It is an amenable number.

21020200222001 is a deficient number, since it is larger than the sum of its proper divisors (24545731).

21020200222001 is an equidigital number, since it uses as much as digits as its factorization.

21020200222001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24545730.

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 21020200222001 its reverse (10022200202012), we get a palindrome (31042400424013).

The spelling of 21020200222001 in words is "twenty-one trillion, twenty billion, two hundred million, two hundred twenty-two thousand, one".