1220776581 has 16 divisors (see below), whose sum is σ = 1721507840. Its totient is φ = 767355120.

The previous prime is 1220776577. The next prime is 1220776673. The reversal of 1220776581 is 1856770221.

It is not a de Polignac number, because 1220776581 - 2² = 1220776577 is a prime.

It is a super-2 number, since 2×1220776581² = 2980590921436099122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220776561) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38725 + ... + 62778.

It is an arithmetic number, because the mean of its divisors is an integer number (107594240).

Almost surely, 2^1220776581 is an apocalyptic number.

It is an amenable number.

1220776581 is a deficient number, since it is larger than the sum of its proper divisors (500731259).

1220776581 is a wasteful number, since it uses less digits than its factorization.

1220776581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101736.

The product of its (nonzero) digits is 47040, while the sum is 39.

The square root of 1220776581 is about 34939.6133493203. The cubic root of 1220776581 is about 1068.7564033405.

It can be divided in two parts, 12207 and 76581, that added together give a palindrome (88788).

The spelling of 1220776581 in words is "one billion, two hundred twenty million, seven hundred seventy-six thousand, five hundred eighty-one".