1220165991461 has 2 divisors, whose sum is σ = 1220165991462. Its totient is φ = 1220165991460.

The previous prime is 1220165991439. The next prime is 1220165991481. The reversal of 1220165991461 is 1641995610221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 649716602500 + 570449388961 = 806050^2 + 755281^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220165991461 - 2⁶ = 1220165991397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1220165991481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610082995730 + 610082995731.

It is an arithmetic number, because the mean of its divisors is an integer number (610082995731).

Almost surely, 2^{1220165991461} is an apocalyptic number.

It is an amenable number.

1220165991461 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220165991461 is an equidigital number, since it uses as much as digits as its factorization.

1220165991461 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 233280, while the sum is 47.

The spelling of 1220165991461 in words is "one trillion, two hundred twenty billion, one hundred sixty-five million, nine hundred ninety-one thousand, four hundred sixty-one".