20757568777 has 4 divisors (see below), whose sum is σ = 22644620496. Its totient is φ = 18870517060.

The previous prime is 20757568739. The next prime is 20757568807. The reversal of 20757568777 is 77786575702.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20757568777 - 2²³ = 20749180169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20757568717) 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, 943525843 + ... + 943525864.

It is an arithmetic number, because the mean of its divisors is an integer number (5661155124).

Almost surely, 2^20757568777 is an apocalyptic number.

It is an amenable number.

20757568777 is a deficient number, since it is larger than the sum of its proper divisors (1887051719).

20757568777 is a wasteful number, since it uses less digits than its factorization.

20757568777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1887051718.

The product of its (nonzero) digits is 40336800, while the sum is 61.

The spelling of 20757568777 in words is "twenty billion, seven hundred fifty-seven million, five hundred sixty-eight thousand, seven hundred seventy-seven".