21212202220001 has 4 divisors (see below), whose sum is σ = 22843910083092. Its totient is φ = 19580494356912.

The previous prime is 21212202219977. The next prime is 21212202220003. The reversal of 21212202220001 is 10002220221212.

It is a happy number.

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 10075291705600 + 11136910514401 = 3174160^2 + 3337201^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21212202220001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21212202220003) 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, 815853931526 + ... + 815853931551.

It is an arithmetic number, because the mean of its divisors is an integer number (5710977520773).

Almost surely, 2^{21212202220001} is an apocalyptic number.

It is an amenable number.

21212202220001 is a deficient number, since it is larger than the sum of its proper divisors (1631707863091).

21212202220001 is a wasteful number, since it uses less digits than its factorization.

21212202220001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1631707863090.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21212202220001 its reverse (10002220221212), we get a palindrome (31214422441213).

The spelling of 21212202220001 in words is "twenty-one trillion, two hundred twelve billion, two hundred two million, two hundred twenty thousand, one".