1220742805 has 4 divisors (see below), whose sum is σ = 1464891372. Its totient is φ = 976594240.

The previous prime is 1220742793. The next prime is 1220742823. The reversal of 1220742805 is 5082470221.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5082470221 = 2753 ⋅1846157.

It can be written as a sum of positive squares in 2 ways, for example, as 430064644 + 790678161 = 20738^2 + 28119^2 .

It is not a de Polignac number, because 1220742805 - 2⁵ = 1220742773 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 122074276 + ... + 122074285.

It is an arithmetic number, because the mean of its divisors is an integer number (366222843).

Almost surely, 2^1220742805 is an apocalyptic number.

It is an amenable number.

1220742805 is a deficient number, since it is larger than the sum of its proper divisors (244148567).

1220742805 is an equidigital number, since it uses as much as digits as its factorization.

1220742805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244148566.

The product of its (nonzero) digits is 8960, while the sum is 31.

The square root of 1220742805 is about 34939.1299977547. The cubic root of 1220742805 is about 1068.7465465958.

The spelling of 1220742805 in words is "one billion, two hundred twenty million, seven hundred forty-two thousand, eight hundred five".