1208394870521 has 2 divisors, whose sum is σ = 1208394870522. Its totient is φ = 1208394870520.

The previous prime is 1208394870491. The next prime is 1208394870539. The reversal of 1208394870521 is 1250784938021.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 707146446400 + 501248424121 = 840920^2 + 707989^2 .

It is a cyclic number.

It is not a de Polignac number, because 1208394870521 - 2¹⁴ = 1208394854137 is a prime.

It is a super-2 number, since 2×1208394870521² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1208394870521.

It is not a weakly prime, because it can be changed into another prime (1208394870581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 604197435260 + 604197435261.

It is an arithmetic number, because the mean of its divisors is an integer number (604197435261).

Almost surely, 2^{1208394870521} is an apocalyptic number.

It is an amenable number.

1208394870521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1208394870521 is an equidigital number, since it uses as much as digits as its factorization.

1208394870521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 967680, while the sum is 50.

The spelling of 1208394870521 in words is "one trillion, two hundred eight billion, three hundred ninety-four million, eight hundred seventy thousand, five hundred twenty-one".