102121220021221 has 4 divisors (see below), whose sum is σ = 103174016104012. Its totient is φ = 101068423938432.

The previous prime is 102121220021167. The next prime is 102121220021273. The reversal of 102121220021221 is 122120022121201.

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 36667699608996 + 65453520412225 = 6055386^2 + 8090335^2 .

It is a cyclic number.

It is not a de Polignac number, because 102121220021221 - 2⁴⁵ = 66936847932389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102121220021281) 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, 526398041250 + ... + 526398041443.

It is an arithmetic number, because the mean of its divisors is an integer number (25793504026003).

Almost surely, 2^{102121220021221} is an apocalyptic number.

It is an amenable number.

102121220021221 is a deficient number, since it is larger than the sum of its proper divisors (1052796082791).

102121220021221 is an equidigital number, since it uses as much as digits as its factorization.

102121220021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1052796082790.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 102121220021221 its reverse (122120022121201), we get a palindrome (224241242142422).

The spelling of 102121220021221 in words is "one hundred two trillion, one hundred twenty-one billion, two hundred twenty million, twenty-one thousand, two hundred twenty-one".