206221201335021 has 16 divisors (see below), whose sum is σ = 275143805365824. Its totient is φ = 137389714952064.

The previous prime is 206221201335013. The next prime is 206221201335181. The reversal of 206221201335021 is 120533102122602.

It is not a de Polignac number, because 206221201335021 - 2³ = 206221201335013 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 206221201335021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206221201835021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50202505 + ... + 54154721.

It is an arithmetic number, because the mean of its divisors is an integer number (17196487835364).

Almost surely, 2^{206221201335021} is an apocalyptic number.

It is an amenable number.

206221201335021 is a deficient number, since it is larger than the sum of its proper divisors (68922604030803).

206221201335021 is a wasteful number, since it uses less digits than its factorization.

206221201335021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3963740.

The product of its (nonzero) digits is 8640, while the sum is 30.

Adding to 206221201335021 its reverse (120533102122602), we get a palindrome (326754303457623).

The spelling of 206221201335021 in words is "two hundred six trillion, two hundred twenty-one billion, two hundred one million, three hundred thirty-five thousand, twenty-one".