20557773236365 has 16 divisors (see below), whose sum is σ = 25052160474288. Its totient is φ = 16191805810176.

The previous prime is 20557773236359. The next prime is 20557773236411. The reversal of 20557773236365 is 56363237775502.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 4143785425641 + 16413987810724 = 2035629^2 + 4051418^2 .

It is a cyclic number.

It is not a de Polignac number, because 20557773236365 - 2⁵ = 20557773236333 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50355642 + ... + 50762251.

It is an arithmetic number, because the mean of its divisors is an integer number (1565760029643).

Almost surely, 2^{20557773236365} is an apocalyptic number.

It is an amenable number.

20557773236365 is a deficient number, since it is larger than the sum of its proper divisors (4494387237923).

20557773236365 is a wasteful number, since it uses less digits than its factorization.

20557773236365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101118528.

The product of its (nonzero) digits is 166698000, while the sum is 61.

The spelling of 20557773236365 in words is "twenty trillion, five hundred fifty-seven billion, seven hundred seventy-three million, two hundred thirty-six thousand, three hundred sixty-five".