1220155757 has 2 divisors, whose sum is σ = 1220155758. Its totient is φ = 1220155756.

The previous prime is 1220155747. The next prime is 1220155759. The reversal of 1220155757 is 7575510221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1215289321 + 4866436 = 34861^2 + 2206^2 .

It is an emirp because it is prime and its reverse (7575510221) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1220155757 is a prime.

Together with 1220155759, 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 (1220155759) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610077878 + 610077879.

It is an arithmetic number, because the mean of its divisors is an integer number (610077879).

Almost surely, 2^1220155757 is an apocalyptic number.

It is an amenable number.

1220155757 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220155757 is an equidigital number, since it uses as much as digits as its factorization.

1220155757 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24500, while the sum is 35.

The square root of 1220155757 is about 34930.7279769546. The cubic root of 1220155757 is about 1068.5752011606.

Adding to 1220155757 its reverse (7575510221), we get a palindrome (8795665978).

The spelling of 1220155757 in words is "one billion, two hundred twenty million, one hundred fifty-five thousand, seven hundred fifty-seven".