20820307155 has 16 divisors (see below), whose sum is σ = 33642320544. Its totient is φ = 10994220800.

The previous prime is 20820307153. The next prime is 20820307169. The reversal of 20820307155 is 55170302802.

It is not a de Polignac number, because 20820307155 - 2¹ = 20820307153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20820307153) 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, 6869874 + ... + 6872903.

It is an arithmetic number, because the mean of its divisors is an integer number (2102645034).

Almost surely, 2^20820307155 is an apocalyptic number.

20820307155 is a deficient number, since it is larger than the sum of its proper divisors (12822013389).

20820307155 is a wasteful number, since it uses less digits than its factorization.

20820307155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13742886.

The product of its (nonzero) digits is 16800, while the sum is 33.

Adding to 20820307155 its reverse (55170302802), we get a palindrome (75990609957).

The spelling of 20820307155 in words is "twenty billion, eight hundred twenty million, three hundred seven thousand, one hundred fifty-five".