1221416201329 has 3 divisors (see below), whose sum is σ = 1221417306507. Its totient is φ = 1221415096152.

The previous prime is 1221416201309. The next prime is 1221416201339. The reversal of 1221416201329 is 9231026141221.

The square root of 1221416201329 is 1105177.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 1218871200625 + 2545000704 = 1104025^2 + 50448^2 .

It is not a de Polignac number, because 1221416201329 - 2³⁵ = 1187056462961 is a prime.

It is a super-2 number, since 2×1221416201329² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221416201294 and 1221416201303.

It is not an unprimeable number, because it can be changed into a prime (1221416201309) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 552589 + ... + 1657765.

It is an arithmetic number, because the mean of its divisors is an integer number (407139102169).

Almost surely, 2^{1221416201329} is an apocalyptic number.

1221416201329 is the 1105177-th square number.

1221416201329 is the 552589-th centered octagonal number.

It is an amenable number.

1221416201329 is a deficient number, since it is larger than the sum of its proper divisors (1105178).

1221416201329 is an frugal number, since it uses more digits than its factorization.

1221416201329 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2210354 (or 1105177 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 34.

The spelling of 1221416201329 in words is "one trillion, two hundred twenty-one billion, four hundred sixteen million, two hundred one thousand, three hundred twenty-nine".