1220305477 has 4 divisors (see below), whose sum is σ = 1222648236. Its totient is φ = 1217962720.

The previous prime is 1220305451. The next prime is 1220305481. The reversal of 1220305477 is 7745030221.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 294259716 + 926045761 = 17154^2 + 30431^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220305477 - 2²³ = 1211916869 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220305417) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1170598 + ... + 1171639.

It is an arithmetic number, because the mean of its divisors is an integer number (305662059).

Almost surely, 2^1220305477 is an apocalyptic number.

It is an amenable number.

1220305477 is a deficient number, since it is larger than the sum of its proper divisors (2342759).

1220305477 is an equidigital number, since it uses as much as digits as its factorization.

1220305477 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2342758.

The product of its (nonzero) digits is 11760, while the sum is 31.

The square root of 1220305477 is about 34932.8710099814. The cubic root of 1220305477 is about 1068.6189061097.

Adding to 1220305477 its reverse (7745030221), we get a palindrome (8965335698).

The spelling of 1220305477 in words is "one billion, two hundred twenty million, three hundred five thousand, four hundred seventy-seven".