221021211101021 has 8 divisors (see below), whose sum is σ = 228643346728920. Its totient is φ = 213399123110208.

The previous prime is 221021211100997. The next prime is 221021211101027. The reversal of 221021211101021 is 120101112120122.

It can be written as a sum of positive squares in 4 ways, for example, as 17076820672921 + 203944390428100 = 4132411^2 + 14280910^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221021211101021 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221021211101027) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2339546 + ... + 21154571.

It is an arithmetic number, because the mean of its divisors is an integer number (28580418341115).

Almost surely, 2^{221021211101021} is an apocalyptic number.

It is an amenable number.

221021211101021 is a deficient number, since it is larger than the sum of its proper divisors (7622135627899).

221021211101021 is a wasteful number, since it uses less digits than its factorization.

221021211101021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23818543.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 221021211101021 its reverse (120101112120122), we get a palindrome (341122323221143).

The spelling of 221021211101021 in words is "two hundred twenty-one trillion, twenty-one billion, two hundred eleven million, one hundred one thousand, twenty-one".