1221110001205 has 8 divisors (see below), whose sum is σ = 1466114357592. Its totient is φ = 976366430208.

The previous prime is 1221110001197. The next prime is 1221110001253. The reversal of 1221110001205 is 5021000111221.

It can be written as a sum of positive squares in 4 ways, for example, as 10744773649 + 1210365227556 = 103657^2 + 1100166^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 1221110001205 - 2³ = 1221110001197 is a prime.

It is a super-2 number, since 2×1221110001205² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 65186044 + ... + 65204773.

It is an arithmetic number, because the mean of its divisors is an integer number (183264294699).

Almost surely, 2^{1221110001205} is an apocalyptic number.

It is an amenable number.

1221110001205 is a deficient number, since it is larger than the sum of its proper divisors (245004356387).

1221110001205 is a wasteful number, since it uses less digits than its factorization.

1221110001205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130392695.

The product of its (nonzero) digits is 40, while the sum is 16.

Adding to 1221110001205 its reverse (5021000111221), we get a palindrome (6242110112426).

The spelling of 1221110001205 in words is "one trillion, two hundred twenty-one billion, one hundred ten million, one thousand, two hundred five".