1173399561621 has 120 divisors (see below), whose sum is σ = 2128038727320. Its totient is φ = 641656608768.

The previous prime is 1173399561613. The next prime is 1173399561661. The reversal of 1173399561621 is 1261659933711.

1173399561621 is a `hidden beast` number, since 1 + 1 + 7 + 3 + 3 + 9 + 9 + 5 + 6 + 1 + 621 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 103031370225 + 1070368191396 = 320985^2 + 1034586^2 .

It is not a de Polignac number, because 1173399561621 - 2³ = 1173399561613 is a prime.

It is a super-2 number, since 2×1173399561621² (a number of 25 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1173399561661) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 12961305 + ... + 13051521.

It is an arithmetic number, because the mean of its divisors is an integer number (17733656061).

Almost surely, 2^{1173399561621} is an apocalyptic number.

It is an amenable number.

1173399561621 is a deficient number, since it is larger than the sum of its proper divisors (954639165699).

1173399561621 is a wasteful number, since it uses less digits than its factorization.

1173399561621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90385 (or 90369 counting only the distinct ones).

The product of its digits is 1837080, while the sum is 54.

The spelling of 1173399561621 in words is "one trillion, one hundred seventy-three billion, three hundred ninety-nine million, five hundred sixty-one thousand, six hundred twenty-one".