20555242154 has 4 divisors (see below), whose sum is σ = 30832863234. Its totient is φ = 10277621076.

The previous prime is 20555242133. The next prime is 20555242157. The reversal of 20555242154 is 45124255502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 45124255502 = 2 ⋅22562127751.

It can be written as a sum of positive squares in only one way, i.e., 13561767025 + 6993475129 = 116455^2 + 83627^2 .

It is not an unprimeable number, because it can be changed into a prime (20555242157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5138810537 + ... + 5138810540.

Almost surely, 2^20555242154 is an apocalyptic number.

20555242154 is a deficient number, since it is larger than the sum of its proper divisors (10277621080).

20555242154 is a wasteful number, since it uses less digits than its factorization.

20555242154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10277621079.

The product of its (nonzero) digits is 80000, while the sum is 35.

Adding to 20555242154 its reverse (45124255502), we get a palindrome (65679497656).

The spelling of 20555242154 in words is "twenty billion, five hundred fifty-five million, two hundred forty-two thousand, one hundred fifty-four".