20205501705 has 16 divisors (see below), whose sum is σ = 35920892160. Its totient is φ = 10776267504.

The previous prime is 20205501671. The next prime is 20205501707. The reversal of 20205501705 is 50710550202.

It is a happy number.

20205501705 is a `hidden beast` number, since 20 + 20 + 550 + 1 + 70 + 5 = 666.

It is not a de Polignac number, because 20205501705 - 2²¹ = 20203404553 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (20205501707) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 74835057 + ... + 74835326.

It is an arithmetic number, because the mean of its divisors is an integer number (2245055760).

Almost surely, 2^20205501705 is an apocalyptic number.

It is an amenable number.

20205501705 is a deficient number, since it is larger than the sum of its proper divisors (15715390455).

20205501705 is a wasteful number, since it uses less digits than its factorization.

20205501705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149670397 (or 149670391 counting only the distinct ones).

The product of its (nonzero) digits is 3500, while the sum is 27.

The spelling of 20205501705 in words is "twenty billion, two hundred five million, five hundred one thousand, seven hundred five".