1201209955591 has 2 divisors, whose sum is σ = 1201209955592. Its totient is φ = 1201209955590.

The previous prime is 1201209955573. The next prime is 1201209955639. The reversal of 1201209955591 is 1955599021021.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1201209955591 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1201209955511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 600604977795 + 600604977796.

It is an arithmetic number, because the mean of its divisors is an integer number (600604977796).

Almost surely, 2^{1201209955591} is an apocalyptic number.

1201209955591 is a deficient number, since it is larger than the sum of its proper divisors (1).

1201209955591 is an equidigital number, since it uses as much as digits as its factorization.

1201209955591 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 364500, while the sum is 49.

The spelling of 1201209955591 in words is "one trillion, two hundred one billion, two hundred nine million, nine hundred fifty-five thousand, five hundred ninety-one".