20506010155 has 4 divisors (see below), whose sum is σ = 24607212192. Its totient is φ = 16404808120.

The previous prime is 20506010153. The next prime is 20506010159. The reversal of 20506010155 is 55101060502.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20506010155 - 2¹ = 20506010153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20506010153) 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, 2050601011 + ... + 2050601020.

It is an arithmetic number, because the mean of its divisors is an integer number (6151803048).

Almost surely, 2^20506010155 is an apocalyptic number.

20506010155 is a deficient number, since it is larger than the sum of its proper divisors (4101202037).

20506010155 is an equidigital number, since it uses as much as digits as its factorization.

20506010155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4101202036.

The product of its (nonzero) digits is 1500, while the sum is 25.

Adding to 20506010155 its reverse (55101060502), we get a palindrome (75607070657).

The spelling of 20506010155 in words is "twenty billion, five hundred six million, ten thousand, one hundred fifty-five".