20268689761 has 4 divisors (see below), whose sum is σ = 20319235524. Its totient is φ = 20218144000.

The previous prime is 20268689677. The next prime is 20268689803. The reversal of 20268689761 is 16798686202.

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 9648150625 + 10620539136 = 98225^2 + 103056^2 .

It is a cyclic number.

It is not a de Polignac number, because 20268689761 - 2¹⁹ = 20268165473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20268689461) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25272280 + ... + 25273081.

It is an arithmetic number, because the mean of its divisors is an integer number (5079808881).

Almost surely, 2^20268689761 is an apocalyptic number.

It is an amenable number.

20268689761 is a deficient number, since it is larger than the sum of its proper divisors (50545763).

20268689761 is an equidigital number, since it uses as much as digits as its factorization.

20268689761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50545762.

The product of its (nonzero) digits is 3483648, while the sum is 55.

The spelling of 20268689761 in words is "twenty billion, two hundred sixty-eight million, six hundred eighty-nine thousand, seven hundred sixty-one".