1228747863121 has 3 divisors (see below), whose sum is σ = 1228748971611. Its totient is φ = 1228746754632.

The previous prime is 1228747863103. The next prime is 1228747863137. The reversal of 1228747863121 is 1213687478221.

It is a happy number.

The square root of 1228747863121 is 1108489.

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., 38903223121 + 1189844640000 = 197239^2 + 1090800^2 .

It is not a de Polignac number, because 1228747863121 - 2²¹ = 1228745765969 is a prime.

It is a super-2 number, since 2×1228747863121² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1228747863221) 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, 554245 + ... + 1662733.

It is an arithmetic number, because the mean of its divisors is an integer number (409582990537).

Almost surely, 2^{1228747863121} is an apocalyptic number.

1228747863121 is the 1108489-th square number.

1228747863121 is the 554245-th centered octagonal number.

It is an amenable number.

1228747863121 is a deficient number, since it is larger than the sum of its proper divisors (1108490).

1228747863121 is an frugal number, since it uses more digits than its factorization.

1228747863121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2216978 (or 1108489 counting only the distinct ones).

The product of its digits is 1806336, while the sum is 52.

The spelling of 1228747863121 in words is "one trillion, two hundred twenty-eight billion, seven hundred forty-seven million, eight hundred sixty-three thousand, one hundred twenty-one".