20091228440977 has 8 divisors (see below), whose sum is σ = 20179213332200. Its totient is φ = 20003245726464.

The previous prime is 20091228440939. The next prime is 20091228441001. The reversal of 20091228440977 is 77904482219002.

It is a Cunningham number, because it is equal to 4482324²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 18711991941696 + 1379236499281 = 4325736^2 + 1174409^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20091228440977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20091228449977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19582399 + ... + 20582827.

It is an arithmetic number, because the mean of its divisors is an integer number (2522401666525).

Almost surely, 2^{20091228440977} is an apocalyptic number.

It is an amenable number.

20091228440977 is a deficient number, since it is larger than the sum of its proper divisors (87984891223).

20091228440977 is a wasteful number, since it uses less digits than its factorization.

20091228440977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1088355.

The product of its (nonzero) digits is 4064256, while the sum is 55.

The spelling of 20091228440977 in words is "twenty trillion, ninety-one billion, two hundred twenty-eight million, four hundred forty thousand, nine hundred seventy-seven".