1220165991437 has 2 divisors, whose sum is σ = 1220165991438. Its totient is φ = 1220165991436.

The previous prime is 1220165991403. The next prime is 1220165991439. The reversal of 1220165991437 is 7341995610221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 935686701481 + 284479289956 = 967309^2 + 533366^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1220165991437 is a prime.

Together with 1220165991439, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1220165991439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610082995718 + 610082995719.

It is an arithmetic number, because the mean of its divisors is an integer number (610082995719).

Almost surely, 2^{1220165991437} is an apocalyptic number.

It is an amenable number.

1220165991437 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220165991437 is an equidigital number, since it uses as much as digits as its factorization.

1220165991437 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 816480, while the sum is 50.

The spelling of 1220165991437 in words is "one trillion, two hundred twenty billion, one hundred sixty-five million, nine hundred ninety-one thousand, four hundred thirty-seven".