102011001221 has 4 divisors (see below), whose sum is σ = 102058208844. Its totient is φ = 101963793600.

The previous prime is 102011001217. The next prime is 102011001277. The reversal of 102011001221 is 122100110201.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 122100110201 = 139 ⋅878418059.

It can be written as a sum of positive squares in 2 ways, for example, as 74332024321 + 27678976900 = 272639^2 + 166370^2 .

It is a cyclic number.

It is not a de Polignac number, because 102011001221 - 2² = 102011001217 is a prime.

It is a super-2 number, since 2×102011001221² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102011003221) 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, 23600570 + ... + 23604891.

It is an arithmetic number, because the mean of its divisors is an integer number (25514552211).

Almost surely, 2^102011001221 is an apocalyptic number.

It is an amenable number.

102011001221 is a deficient number, since it is larger than the sum of its proper divisors (47207623).

102011001221 is an equidigital number, since it uses as much as digits as its factorization.

102011001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47207622.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 102011001221 its reverse (122100110201), we get a palindrome (224111111422).

The spelling of 102011001221 in words is "one hundred two billion, eleven million, one thousand, two hundred twenty-one".