20990277361 has 4 divisors (see below), whose sum is σ = 21040135924. Its totient is φ = 20940418800.

The previous prime is 20990277337. The next prime is 20990277389. The reversal of 20990277361 is 16377209902.

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 10281960000 + 10708317361 = 101400^2 + 103481^2 .

It is a cyclic number.

It is not a de Polignac number, because 20990277361 - 2⁹ = 20990276849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20990271361) 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 3 ways as a sum of consecutive naturals, for example, 24928650 + ... + 24929491.

It is an arithmetic number, because the mean of its divisors is an integer number (5260033981).

Almost surely, 2^20990277361 is an apocalyptic number.

It is an amenable number.

20990277361 is a deficient number, since it is larger than the sum of its proper divisors (49858563).

20990277361 is an equidigital number, since it uses as much as digits as its factorization.

20990277361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49858562.

The product of its (nonzero) digits is 285768, while the sum is 46.

The spelling of 20990277361 in words is "twenty billion, nine hundred ninety million, two hundred seventy-seven thousand, three hundred sixty-one".