20205506077 has 4 divisors (see below), whose sum is σ = 21394065276. Its totient is φ = 19016946880.

The previous prime is 20205506063. The next prime is 20205506093. The reversal of 20205506077 is 77060550202.

It is a happy number.

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 10014805476 + 10190700601 = 100074^2 + 100949^2 .

It is a cyclic number.

It is not a de Polignac number, because 20205506077 - 2⁷ = 20205505949 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20205506017) 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, 594279574 + ... + 594279607.

It is an arithmetic number, because the mean of its divisors is an integer number (5348516319).

Almost surely, 2^20205506077 is an apocalyptic number.

It is an amenable number.

20205506077 is a deficient number, since it is larger than the sum of its proper divisors (1188559199).

20205506077 is a wasteful number, since it uses less digits than its factorization.

20205506077 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1188559198.

The product of its (nonzero) digits is 29400, while the sum is 34.

The spelling of 20205506077 in words is "twenty billion, two hundred five million, five hundred six thousand, seventy-seven".