1226199660921 has 27 divisors (see below), whose sum is σ = 1869399680421. Its totient is φ = 774402026904.

The previous prime is 1226199660919. The next prime is 1226199660947. The reversal of 1226199660921 is 1290669916221.

The square root of 1226199660921 is 1107339.

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

1226199660921 is a `hidden beast` number, since 1 + 2 + 2 + 6 + 1 + 9 + 9 + 6 + 609 + 21 = 666.

It is not a de Polignac number, because 1226199660921 - 2¹ = 1226199660919 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1226199660221) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 63108610 + ... + 63128036.

Almost surely, 2^{1226199660921} is an apocalyptic number.

1226199660921 is the 1107339-th square number.

1226199660921 is the 553670-th centered octagonal number.

It is an amenable number.

1226199660921 is a deficient number, since it is larger than the sum of its proper divisors (643200019500).

1226199660921 is an frugal number, since it uses more digits than its factorization.

1226199660921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38898 (or 19449 counting only the distinct ones).

The product of its (nonzero) digits is 1259712, while the sum is 54.

The spelling of 1226199660921 in words is "one trillion, two hundred twenty-six billion, one hundred ninety-nine million, six hundred sixty thousand, nine hundred twenty-one".